Elevating Progress with Sustainable Solutions

Materials. Powering Ideas. Elevating Progress with Sustainable Solutions Sustainability and Corporate Social Responsibility Report July 2015

OUR COMMITMENT TO SUSTAINABILITY Trinseo is a preferred partner for sustainable solutions in plastics, latex, and rubber. We listen to our customers sustainability needs to help them continuously improve the sustainability performance of their products and the success of their value chain. We put our entrepreneurial nature, laser focus, and flexibility to work to provide the marketplace with tangible and sustainable next-generation solutions. The people of Trinseo are committed to improving Trinseo s economic, environmental, and social performance through: Innovating and developing new and improved products and processes that enhance our customers sustainability Promoting the responsible use of our materials through product stewardship Operating responsibly with respect to the environment, health and safety, and efficient use of resources Adhering to the principles of Responsible Care Being a good neighbor in the communities where we operate Monitoring, measuring, reporting, and improving Trinseo s performance continuously Responsible Care is a registered service mark of the American Chemistry Council in the United States 2 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

TABLE OF CONTENTS Our Commitment to Sustainability...2 MESSAGE FROM THE CEO Message from the CEO...3 Sustainability Highlights 2014...4 Our vision is to be a world leader delivering innovative materials, technologies, and solutions that enable a more sustainable world. At Trinseo, our sustainability commitment is an integral part of our business strategy. Our focus and dedication will propel us to that end, while allowing us to help our customers do the same. Trinseo s plastics, latex, and rubber products enable our customers to create more sustainable solutions by reducing energy use, preserving health, enhancing safety, improving durability, and conserving natural resources. This report highlights a number of examples where Trinseo products enable lighter weight cars, energy-saving green tires, LED lighting, life-saving medical devices, and much more. Our facilities also are continuously improving their sustainability efforts. This report outlines our programs in product stewardship, quality, ethics and compliance, volunteerism, and Responsible Care. We continue our work to reduce Trinseo s environmental footprint, while developing new innovative solutions that benefit our world. None of this would be possible without the outstanding efforts of Trinseo people across the globe who demonstrate their commitment to sustainability every day. Chris Pappas President and CEO, Trinseo Sustainable Products...5 Lightweight Solutions Make a Weighty Difference...6 Sustainable Plastics Solutions that Deliver Big Results...7 The Continuing Evolution of Polystyrene...8 Resins for LED Technology Light the Way to Increased Energy Efficiency...9 Green Tires Deliver Gripping Results...10 PCR Plastics Divert Materials from Landfills...11 Concrete Additive Increases Sustainability of Highway Infastructure...12 Latex Coating Enhances Environmentally Friendly Paperboard...12 Engineering Polymers Control the Spread of Infection in Healthcare...13 Resins Help Electric Vehicles Charge Up...14 Sustainable Performance...15 Economic Performance...16 Financial Performance...17 Environmental Performance...18 Key Environmental Performance Indicators... 23 Social Performance...27 Human Resources Performance...28 Sustainable Operations...32 Quality...33 Suppliers...35 Product Safety...35 Regulatory Compliance...37 Operational Efficiencies...40 Our Commitments...41 Core Values...42 Environmental, Health and Safety Policy...42 Responsible Care...43 Ethics and Compliance...44 Social Media Efforts Expanded...45 Throughout this document, Trinseo or the Company refers to Trinseo LLC and the Trinseo companies, affiliates, and subsidiaries. Responsible Care is a registered service mark of the American Chemistry Council in the United States. (Click on Table of Contents topic for specific page) 3 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

SUSTAINABILITY HIGHLIGHTS 2014 23% Reduction in emissions of volatile organic chemicals (VOCs) (vs. 2013) 21% Reduction in emissions of non-voc chemicals (vs. 2013) 75% Reduction in energy consumption by using an LED bulb with Trinseo plastic lens, compared to traditional incandescent light 4% 5% Potential reduction in amount of raw materials and costs to transport these raw materials due to refrigerator liner advancements which require less raw material (assuming 75,000 tonnes of product shipped across EMEA annually) Potential weight reduction per 100 grams of Trinseo PULSE GX50 Resin in plastic auto parts versus industry-standard PC/ABS 80 liters or 3% Reduction in fuel consumption when using low rolling resistance tires with SSBR rubber from Trinseo Percent of Trinseo manufacturing plants with Triple Zero record: no injuries, no significant spills, no process safety incidents 70% 95% Percent of Trinseo employees who completed ethics and compliance training 58% Percent of Trinseo plants with ISO 14001 certification 27% Percent of Trinseo sites with ISO 50001 certification 2% Reduction in electricity use (vs. 2013) 37% Reduction in waste (vs. prior year) 4 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

SUSTAINABLE PRODUCTS As a preferred partner for sustainable solutions in plastics, latex, and rubber products, Trinseo listens to its customers sustainability needs and strives to deliver innovative products and technologies that help Trinseo and its customers improve their economic, environmental, and social performance. 5 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Lightweight Solutions Make a Weighty Difference 4% The automotive market is demanding lightweight solutions, driven in a large part by legislation such as CARS 2020 in Europe and CAFE in the U.S., both of which aim to increase fuel economy in vehicles. Trinseo Automotive is meeting the need with innovative engineering and low density materials. Decreased Numbers Add Up to Big Savings Trinseo PULSE GX50 Resin is an optimized mixture of polycarbonate (PC) and acrylonitrile butadiene styrene (ABS) specially blended for use in unpainted applications. The material offers a four percent decrease in density and proprietary UV stabilizing technology. Trinseo resin can reduce part costs by up to 50 percent, according to auto manufacturers and their suppliers. One early adopter was BMW. Their decision to choose PULSE GX50 technology was based on several key factors. The lightweight UV stabilizing technology from Trinseo enabled BMW to replace highly visible, painted interior parts with high quality unpainted parts, resulting in fewer production steps, a 50 percent reduction in the cost of parts, and a positive effect on the environment. These combined benefits were the basis for BMW s decision to use Trinseo PULSE GX50 technology for their interior applications, and it has been used extensively in the BMW i3. Trinseo resin has also been used in Daimler AG s Mercedes Benz C-class automobiles. Potential weight reduction per 100 grams of Trinseo PULSE GX50 Resin in plastic auto parts versus industry-standard PC/ABS The Future Weighs Less Structural Polymers Are a Lightweight Solution to Steel and Aluminum Automotive manufacturers are looking for robust, affordable solutions to address the demand for lightweight components. One application where Trinseo delivers sought-after requirements that enable lightweighting stiffness, dimensional stability, and thermal resistance is the lift-gate. A lift-gate must conceal numerous elements, such as hinges, closing mechanisms, and electrical wiring. Additionally, it is exposed to climatic conditions, including high/low temperatures and humidity, which can cause deformation. Replacing steel and aluminum components with Trinseo polypropylene long glass fiber (PP LGF) or another glass fiber alloy may save up to 20 percent mass and costs, as well as meet these additional requirements. Due to the availability of this innovative lightweight solution, Renault chose Trinseo as its supplier of polypropylene LGF specifically for the 2015 Renault Espace. The lift-gate and the front end carrier of the Espace will be made out of Trinseo PP LGF and will allow Renault to achieve significant weight reductions of 10 percent. With every one kilogram of reduction in weight in a car, fuel consumption decreases, which results in reduced CO 2 emissions. 1 In addition, recycling is easier because the two components which make up the lift-gate (an inner skin and the structural component) are both made of the same base material, mineral filled polypropylene so the lift-gate does not have to be disassembled to be recycled. Trinseo materials continue to contribute to weight reduction, delivering optimal fuel efficiency while responding to recycling needs. Ultimately, lightweighting reduces fuel consumption and CO 2 emissions which are better for our environment. 1 European Federation for Transport and Environment, Cars and CO 2 6 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Sustainable Plastics Solutions that Deliver Big Results Door Module ENLITE PP LGF 4001 Weight saving per part -30% Mid Console and Seat Trim PULSE GX50 Weight saving per part -4% Bumper INSPIRE TF1806Z PR Weight saving per part -5% Blow-molded Seatback PULSE 6000 BG Weight saving per car -1.65kg Weight saving per car -0.05kg Weight saving per car -0.36kg Weight saving per part -25% CO 2 reduction over the lifespan of vehicle -33kg CO 2 reduction over the lifespan of vehicle -1kg CO 2 reduction over the lifespan of vehicle -7kg Weight saving per car -2kg CO 2 reduction over the lifespan of vehicle -40kg Lift-gate ENLITE PP LGF 6002 Weight saving per part -10% Weight saving per car -2kg CO 2 reduction over the lifespan of vehicle -40kg Total Glove Box and IP Trim PULSE GX50 Air Gate ENLITE PP LGF 6002 Pillars and Trims PULSE GX50 Weight saving per part -4% Weight saving per part -20% Weight saving per car -6.7kg CO 2 reduction over the lifespan of vehicle -134kg Fuel reduction over the lifespan of vehicle -64.4l 1 kg weight reduction = 0.004l/100km 0.1g CO 2/km Car longevity = 200,000 miles or 250,000km In comparison with parts made from industry-standard materials Weight saving per part Weight saving per car CO 2 reduction over the lifespan of vehicle -4% -0.15kg -3kg Weight saving per car CO 2 reduction over the lifespan of vehicle -0.1kg -2kg Weight saving per car CO 2 reduction over the lifespan of vehicle -0.39kg -8kg 7 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

The Continuing Evolution of Polystyrene Trinseo is an industry leader in resins for home appliances. Our R&D teams are committed to continuously developing new, innovative products and improving current products used in a range of home appliance parts. 5% *Potential reduction in amount of raw materials and costs to transport these materials due to refrigerator liner advancements which require less raw material (assuming 75,000 tonnes of product shipped across EMEA annually) Less is More For the last 25 years, high impact polystyrene (HIPS) has been the material of choice in the liner inside refrigerators. Early generations of refrigerator liners required a thick sheet and therefore increased amounts of raw material. The thicker sheet also required substantial amounts of energy during production and shaping. Due to ongoing innovations in resin technology, Trinseo set a new industry standard with STYRON A-TECH 1175 Advanced Polystyrene Resin. This high impact polystyrene (HIPS) resin, which offers balanced toughness, environmental stress crack resistance (ESCR), and processability, enabled refrigerator manufacturers to reduce the thickness of liners by 10 percent without compromising physical properties or chemical resistance. This also translated to as much as a 10 percent energy reduction in the manufacture and thermoforming of the sheet. 2 Today, Trinseo continues to push new downgauging boundaries and works to develop the next generation ESCR HIPS, which will allow for a further reduction in liner thickness by at least an additional five percent. This will result in a five percent reduction in the amount of raw materials used and in the costs associated with the transportation of the raw materials* and storage costs. This will also reduce the amount of energy needed to extrude the polymer and thermoform the sheet into a refrigerator liner, which means a further reduction in energy consumption. 2 Throne, James L., Thermoforming Handbook, Hanse Publishers, 1987, Munich/New York, p. 65. 8 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Resins for LED Technology Light the Way to Increased Energy Efficiency Polycarbonate-based Materials Maximize Benefits of LED Technology LED lighting provides improved levels of energy efficiency, durability, and long life in lighting, resulting in a reduction of energy consumption on a local and global scale. By 2030, the annual site energy savings from conversion to LEDs will be approximately 297 terawatt-hours enough electricity to power 24 million homes. At today s energy prices, that equates to approximately $30 billion in savings in 2030 alone. In addition, assuming the same mix of power plants, these energy savings would reduce greenhouse gas emissions by 210 million metric tons of carbon in 2030. 3 The LED lighting industry faces a number of challenges, for example, achieving uniform light distribution, while maintaining maximum light output. Lens materials that meet this challenge are critical to the effectiveness and efficiency of the LED light source. While the LED chip has longevity, it also needs to be protected from the environment, which requires impact strength in a lens. In addition, resins from Trinseo allow design flexibility and easy fabrication, which are needed in order to produce advanced lighting configurations. Trinseo develops polycarbonate-based materials that enable its customers to maximize the benefits of LED technology. Trinseo plastics used in lenses and housings can protect the costly light source and also balance transmission and diffusion of light to ensure maximum light is released, which enhances efficiency. 75% Reduction in energy consumption by using an LED bulb with Trinseo plastic lens, compared to traditional incandescent light Proprietary light diffusion technology from Trinseo addresses the ongoing industry challenge called the LED hot spot. Our technology offers excellent LED hot spot hiding capability while minimizing light loss. Because Trinseo resins have been qualified and are used by several leading lighting OEMs for LED A lamp and T lamp production globally, our materials can be found in major retail chains across North America. By 2020, LED lighting is expected to represent 36 percent of all lighting sales on the general illumination market and 74 percent by 2030. 3 3 Energy Savings Potential of Solid-State Lighting in General Illumination Applications, U.S. Department of Energy (DOE) update of its report forecasting the energy savings potential of LED white-light sources. 9 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Green Tires Deliver Gripping Results 80 liters or 3% Trinseo Rubber on the Road to Innovation Consumers worldwide are shifting toward green tires with lower rolling resistance, which results in increased energy efficiency and decreased fuel costs and carbon emissions. In response, manufacturers are increasing production of green tires that minimize rolling resistance without sacrificing safety (wet grip) and performance (high abrasion resistance). In 2014, Trinseo introduced two new additions to its range of SPRINTAN Solution Styrene Butadiene Rubber (SSBR), which are tailored to meet the evolving needs of the global tire industry. These next-generation solutions allow an optimum balance of low rolling resistance and high abrasion resistance, and reduced stiffness at low temperatures which boosts snow grip potential in winter tread applications. Both new grades of functionalized SSBR can partially replace traditional rubber grades. Tires incorporating Trinseo s SSBR technology help reduce fuel consumption and greenhouse gas emissions. Lower rolling resistance means that drivers use less energy to travel the same distance. Tires can account for 20 to 30 percent of total fuel consumption. 4 By using lower rolling resistance tires produced with SSBR grades from Trinseo, a driver can reduce fuel consumption up to three percent. Over a typical life span of a set of tires about 45,000 kilometers that could mean savings of up to 80 liters of fuel compared to traditional tires. Reduction in fuel consumption when using low rolling resistance tires with SSBR rubber from Trinseo 4 Transportation Research Board Special Report No. 286, Tires and Passenger Vehicle Fuel Economy, National Research Council of the National Academies, pp. 42-51, 2006. 10 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

PCR Plastics Divert Materials from Landfills Recycling materials that would otherwise wind up in a landfill is one way to protect the environment. The greater the percentage of recycled content in a new material, the more positive the impact is on the environment. The Trinseo portfolio of post-consumer recycled (PCR) plastics was developed in collaboration with customers who want to incorporate recycled materials into their products. Trinseo s PCR grades named ECO incorporate recycled material from large water bottles, compact discs, and other plastic items in various proportions. The objective and the challenge is to maintain performance properties in PCR plastics that may have a significant recycled component. To meet these technical challenges and industry demands, Trinseo s technical team optimizes its PCR product recipes to balance characteristics such as flow, impact strength, and thermal stability. Ultimately, these efforts help reduce overall environmental impact with materials diverted from landfills, while reducing the carbon footprint in the production of finished high-quality products. 11 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Concrete Additive Increases Sustainability of Highway Infrastructure Many parts of the developing world lack quality infrastructure such as roads, bridges, and airports while in developed nations such as the U.S., aging infrastructure is crumbling. Every nation needs robust infrastructure to keep their economy moving, and Trinseo s Modifier A /NA Latex is helping to support highway infrastructure reconstruction efforts and sustainability goals. As an additive to concrete used for road repairs, Modifier A /NA Latex improves durability and resistance to permeation and is among the preferred materials for refurbishing bridge decks, elevated roadways, parking decks, and other structures. Used as a substrate laid over the existing road surface, it provides a good driving surface and resists the effects of deicing salts used on roadways. For bridges and overpasses, in particular, reusing existing roadway span reduces environmental impact and results in significantly less construction debris entering landfills. The oldest bridge deck that used Modifier A /NA Latex in an overlay installation is now more than 35 years old with no evidence of needing repair or replacement. As a material that extends the life of road surfaces, Trinseo s Modifier A /NA Latex helps make infrastructure more durable and sustainable, while enabling transportation and economic growth. Latex Coating Enhances Environmentally Friendly Paperboard Paperboard used in consumer packaging originates from trees, a renewable resource, and is highly recyclable. In 2012, paper and paperboard represented 75 percent of all packaging recovered for recycling in the U.S. 5 Latex coating plays an essential role in paperboard, providing stiffness and moisture resistance, as well as a bright and smooth surface for printing. Most paperboard used in the packaging of food and consumer products is made from recycled paper, and without the coating to hold the recycled fibers together, most paperboard would fall apart before the package arrived at the consumer s home. As consumer goods manufacturers look to include more recycled content in their packaging, paperboard coated with latex from Trinseo will play an important role in meeting the demand for sustainable packaging. 5 According to the Paperboard Packaging Alliance, Paperboard Packaging Fact Sheet 12 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Engineering Polymers Control the Spread of Infection in Healthcare Chemical-resistant Polymers Designed for Device Housings Healthcare-associated infections (HAIs) can be serious and even deadly, and are one of the most pressing concerns in the healthcare industry. The World Health Organization and other governing bodies are calling on the healthcare industry to prevent the spread of bacteria and microorganisms leading to HAIs. One recommendation is to clean all medical equipment surfaces many of which are made from engineering plastics with specific disinfectants and cleansers. While effective at sterilizing the medical devices, these cleansers can compromise the performance characteristics of the plastic, leading to cracking and crazing. EMERGE 9000 Advanced Resins from Trinseo are resistant to the nine leading chemical agents that are most likely to be used in disinfection and sterilization, while maintaining necessary properties for medical devices, such as strength, toughness, clarity, and biocompatibility. Whether in a hospital, nursing home, or doctor s office, advanced resins from Trinseo can play an essential role in reducing a patient s risk of exposure to microorganisms during their treatment ultimately providing both the healthcare provider and the patient with peace of mind. 13 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Resins Help Electric Vehicles Charge Up Polycarbonate Blends Satisfy Critical Requirements for Charging Stations The switch to alternative energy sources and low-emissions vehicles is a growing global trend. As a result, nearly every automobile manufacturer has placed an emphasis on launching an electrical vehicle (EV). Experts forecast that EV sales will grow from 2.7 million vehicles in 2014 to 6.4 million vehicles in 2023. 6 But creating electric vehicles isn t the only thing needed to get these cars on the road. Communities will need new infrastructure, such as charging stations, to support the alternative energy. As a material supplier to the automotive and electrical industries, Trinseo is providing the materials needed to build EV charging stations to keep electric vehicles powered up. Resins for charging stations require transparency and opacity in a wide range of colors, toughness to prevent tampering and resist impact, and flame retardancy to assure safety. Trinseo is working with manufacturers of charging station housings to specify polycarbonate blends that are durable enough to withstand weather extremes of temperatures as low as -60 C. As communities around the world support the movement towards more energy efficient transportation, Trinseo is right behind them, helping to create solutions for a more sustainable future. 6 Navigant Research, Electric Vehicle Market Forecasts, October 2014 14 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

SUSTAINABLE PERFORMANCE Since Trinseo s formation in 2010, the company has made great strides in each of the key areas of sustainability: economic, environmental, and social performance. Although this is our fifth sustainability and corporate responsibility report, this is the third year Trinseo is publicly reporting its environmental performance and emissions data. 15 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Economic Performance Trinseo executive leadership team at the NYSE to ring the opening bell and celebrate the Trinseo IPO in June 2014 NYSE: TSE IPO Marks the Beginning of a New Chapter in the Company s Journey to Independence In June 2014, Trinseo launched its initial public offering (IPO), listing its shares on the iconic New York Stock Exchange (NYSE) under the symbol TSE. Table 1: Selected Financial Data* Sales Adjusted EBITDA Current Assets 2014 5,128 At the time of the IPO, Trinseo aimed to raise between $170 and $190 million through the sale of 10 million common shares. On June 12, the trading began on the floor of the NYSE. Just 24 hours later, on June 13, the executive leadership team (ELT) rang the stock exchange s opening bell. Fifty employees, from all levels of the organization, were in attendance to celebrate Total Assets Current Liabilities Total Liabilities Equity * in millions of dollars 2,356 544 2,035 321 this milestone in the company s history, while sites from around the globe watched a live web stream of the bell ringing. Most Trinseo locations held special activities to celebrate the company s achievement and employees hard work during the transformation. 262 1,323 On June 17, Trinseo announced the IPO closing of 11.5 million ordinary shares at a price of $19 per share, receiving approximately $197.3 million of proceeds from the offering, net of underwriting fees and estimated expenses. The completion of Trinseo s IPO was almost four years to the day since its spin-off as a collection of businesses that were bought by Bain Capital Partners from The Dow Chemical Company. In that short time, Trinseo established a new, strong company and built its reputation and credibility with customers, suppliers, and investors. The IPO marked the beginning of an exciting new chapter for Trinseo as a publicly traded company. Additional financial figures are available at investor.trinseo.com. 16 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Financial Performance Highlights Figure 1: Revenue FEB APR JUN JUL Board approved plan to expand latex capacity in Zhangjiagang, China, with the addition of a new reactor to support the growing paper and paperboard industry, to be completed Q3, 2015 Enhanced Solution Styrene Butadiene Rubber (SSBR) production capacity in Schkopau, Germany, with full capacity rights Announced plans to convert the Nickel Butadiene Rubber (Ni-BR) production train to Neodymium Butadiene Rubber (Nd-BR) to grow the rubber business and broaden product range Celebrated initial public offering on the New York Stock Exchange (symbol TSE) Revenue ($B) 7 6 5 4 3 2 1 0 6.2 5.5 5.3 5.1 2011 2012 2013 2014 $5.1 Revenue/Net Sales 2.4 Billion Basic Plastics and Feedstocks 2.7 Billion Performance Materials Billion $262 Million Adjusted EBITDA IPO opening stock trades at $19.00 per share at 11.5 million shares OCT Early pay down of $132.5 million of senior secured notes funded by proceeds from IPO Realigned business divisions (Performance Plastics and Basic Plastics & Feedstocks); grouped similar strategies together to operate more effectively 17 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Environmental Performance Trinseo takes environmental, health, and safety (EH&S) performance very seriously. Since the first day of the company s formation in 2010, leaders across Trinseo have emphasized that EH&S performance is one of the company s top priorities. Leadership is highly engaged in EH&S activities, setting the right tone, maintaining high expectations, and recognizing positive EH&S results. For example, each biweekly meeting of the Trinseo Leadership Team begins with a report on EH&S performance. Senior leadership is actively involved in the reporting and investigation of every reportable safety incident, as well as giving recognition awards for those work groups with excellent EH&S records. Trinseo executive leadership sets stretch targets each year for improving EH&S/Responsible Care performance around three key metrics: safety incidents (injuries and illnesses), incidents of loss of primary containment (spills and leaks), and process safety incidents (including fires and explosions). Established each January, the annual EH&S targets, along with financial targets, are measured throughout the year and reported in quarterly updates to employees, as well as on Trinseo s Intranet. For every incident, Trinseo conducts a thorough root-cause analysis, takes corrective action when needed, and shares learnings globally to improve performance. It s this approach, along with a comprehensive set of company standards and an audit program, that has enabled Trinseo to outperform the industry in these areas. As a global company, Trinseo is committed to operating in a sustainable manner, including being a good neighbor locally and globally, helping to find solutions to issues around the world. As a plastics producer, Trinseo is engaged via our partners, PlasticsEurope and American Chemistry Council (ACC). In 2013, Trinseo joined the World Plastics Council (WPC), a coalition of leading plastics producers committed to accelerating cooperation and alignment at an international level to deliver improved outcomes for the common benefit of society, consumers, and the plastics industry. In addition, Trinseo is a supporter of the Marine Litter Solutions Coalition, the plastic industry s initiative for the protection of seas and oceans. Trinseo Makes Pledge to Operation Clean Sweep Trinseo Joins Other Companies Striving for Zero Pellet Loss In 2014, Trinseo made the pledge to the environmental stewardship program, Operation Clean Sweep (OCS). Operation Clean Sweep is an international program focused on preventing plastics pellet loss with the objective of keeping plastics granules out of the marine environment, including the world s oceans, seas, and rivers. OCS provides members with tools to ensure that resins producers are following good housekeeping and pellet containment best practices. The program also strives to ensure minimal plastic pellet loss occurs during production, operation, and transportation. 18 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Fishing for Litter Despite many efforts to reduce marine litter, it still remains a problem around the world. As an advocate for recycling and reducing environmental impact, the Trinseo manufacturing site in the Netherlands sponsored the Fishing for Litter campaign developed by Kommunenes Internasjonale Miljøorganisasjon (KIMO). This imaginative yet simple initiative aims to reduce marine litter. To capture attention, KIMO designed a giant globe made from recycled plastics from everyday items, such as water bottles and plastic bags. The globe was the centerpiece of an exhibition that traveled by ship from the harbor of Vlissingen to the harbor of Terneuzen to educate elementary school students in Zeeland, Netherlands, and Vlaanderen, Belgium, through a variety of interactive workshops. Although the campaign targeted children, its message reached consumers of all ages worldwide and served as a simple reminder to recycle more plastics and keep our oceans clean. TOP Students joined hands-on workshops designed to reiterate the importance of recycling and educate consumers about the recycling process. BOTTOM The giant globe towered over visitors as they got closer to see what recycled goods were repurposed to build the structure. 19 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Recordable Injuries Consistent with guidelines published by the U.S. Occupational Safety and Health Administration (OSHA), Figure 2 summarizes the recordable injuries per 200,000 hours worked that have occurred at Trinseo facilities, compared to other manufacturers. Unlike many others in Figure 2: Injury Rate Comparison (injuries per 200,000 hours worked) 5 4 3 2 1 0 Manufacturing 4.3 Chemistry Related 2.4 ACC Members 0.7 Trinseo 0.3 Data for the first point is from the Bureau of Labor Statistics for 2013 (U.S. only). Data for the second and third points are for American Chemistry Council member companies for 2013. the chemical industry, Trinseo includes contract employees in its reporting of recordable injuries. Recordable injuries include all injuries to workers (unless the injury is clearly not work-related) in which a worker requires medical treatment, is restricted by a doctor from certain duties (i.e., lifting objects), or misses work under doctor s orders. Figures 3 and 4 illustrate Trinseo s global injury count and rate, respectively. Figure 3: Injury Count 20 15 10 5 0 Figure 4: Injury Rate 1.0 0.8 0.6 0.4 0.2 3 2010.10 4 2011.14 8 2012.28 9 2013 8 2014.32.28 Loss of Primary Containment (LOPC) LOPC refers to spills and leaks of chemicals. Specifically, this performance metric includes the following: spills of any material other than water or a smaller spill that causes injury, affects the community, or is reported in the news media; Figure 5 summarizes Trinseo s LOPC incidents. Figure 5: Loss of Primary Containment 40 30 20 10 0 11 2010 2011 2012 Internally defined metric 5 2013 2014 Essentially spills of greater than 100 lbs. 8 5 5 0 2010 2011 2012 2013 2014 The injury rate is defined by OSHA rules as injuries per 200,000 hours worked, and is about the same as percent of employees injured in a year. Trinseo count is global and includes contractors for 2014. 20 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Process Safety Incidents (PSI) An incident is considered to be a PSI if it consists of one or more of the following: any explosion or fire with over $25,000 in damage; any large acute chemical release of a flammable or toxic chemical; and any small chemical release causing serious injury. Figure 6 summarizes Trinseo s PSI incidents. Figure 6: Process Safety Incidents 5 4 3 2 1 0 2 2010 2011 1 1 1 2012 0 2013 2014 Safety Only Takes a Minute Building on Our Culture of Safety At Trinseo, safety is more than numbers it is embedded in our culture. We continually strive to protect the health and safety of our employees and contractors. In June 2014, we launched a series of Safety Minute videos with the goal of maintaining and growing the safety mindset throughout the company. Each video explained complicated subjects in their simplest form, reflecting our core values that focus on universal EH&S principles. Each one- to two-minute video addressed a single safety topic. Topics included driving safety, ergonomics, spills, and how to accept and incorporate safety suggestions. Videos were released every two weeks through the end of 2014 and were then archived for use in new employee orientation. To learn more, watch a Safety Minute Video on stair safety. Criteria same as American Chemistry Council Our customers are more interested in sustainability than ever before. And we re here to help them with materials solutions that enhance their products sustainability whether that s through lighter weight, greater durability, higher quality, lower emissions, or a reduced CO 2 footprint. Chemistry and materials science are key to solving the world s sustainability challenges, and we are proud to be a part of that vital effort. Catherine Maxey, VP, Public Affairs, Sustainability, and EH&S 21 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Zero: The Magic Number Recognizing Excellence in EH&S Performance Zero recordable injuries. Zero spills. And zero process safety incidents. Trinseo leadership believes in the vision of zero with the ultimate goal of zero on-the-job injuries in each of our facilities. Each year, that s the goal for all Trinseo facilities globally. With safety being the company s number one priority, Trinseo created an internal award called the Triple Zero Award (000) to both recognize and reward sites that operate and respond according to environmental health and safety best practices. In 2014, 20 Trinseo plants and three global Research & Development and Technical Service & Development groups around the world qualified for the 000 the second time in company history where 23 teams have earned this achievement. (A total of 33 facilities are eligible.) To celebrate, the winning teams each received a banner for the site, control room, or common areas and participated in local celebrations. In addition, each team member received a personalized gift item with the Triple Zero Award logo. While zero recordable injuries, spills, and process safety incidents is an ambitious goal, these teams have demonstrated that with the right education and plenty of hard work, our vision of zero is achievable. Trinseo employees at Hinschu, Taiwan (left) and Schkopau, Germany (right) sites celebrate their Triple Zero Achievements. 70% Percent of Trinseo manufacturing plants with Triple Zero record: no injuries, no significant spills, no process safety incidents 22 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Key Environmental Performance Indicators Figure 7: Electricity Use Figure 8: Electricity by Fuel Source 2014 Megawatt Hours (000) 600 500 400 300 300 100 0 550 531 520 508 2011 2012 2013 2014 2% Reduction in electricity use Trinseo electricity from renewable sources: 23,000 MWhrs from wind, hydroelectric, and solar Coal 44% Oil 1% Nuclear 5% Renewable Natural Gas 4% 46% 2% Reduction in electricity use (vs. 2013) 23 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Key Environmental Performance Indicators Figure 9: Waste Kg (000) 20,000 16,000 12,000 8,000 4,000 0 20,108 14,796 13,289 9,380 2011 2012 2013 2014 Wastewater Landfill Energy Recovery Combustion 37% Reduction in waste from prior year Figure 10: Waste Intensity 6.7 Waste per unit of product manufactured 7 6 5 4 3 2 1 0 2011 4.7 2012 5.6 2013 3.6 2014 37% Reduction in waste (vs. prior year) 24 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Key Environmental Performance Indicators Figure 11: Chemical Emissions Kg (000) 160 120 80 40 0 151 156 153 121 2011 2012 2013 2014 Other Chemical Emissions VOC Emissions 23% Reduction in VOC emissions 21% Reduction in total emissions Reduction in emissions of non-voc chemicals (vs. 2013) 21% Figure 12: Water Consumption Cubic Meters (000) 1,400 1,200 1,000 800 600 400 200 0 1,216 1,193 2011 2012 1,122 2013 1,137 2014 25 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Key Environmental Performance Indicators Figure 13: Greenhouse Gas Emissions Metric Tonnes (000) 800 600 400 200 0 349 2011 684 757 747 748 277 280 286 2012 2013 2014 Scope 1 Scope 2 Greenhouse Gas (GHG) Intensity = Scope 1+2 per tonne of product produced Scope 1: Emissions from sources that are owned or controlled by the company. Scope 2: Emissions from the generation of electricity purchased by the company. Figure 14: GHG Emissions by Value Center Rubber 34% Latex 8% Plastic 21% Feedstocks 37% Trinseo participates in the Carbon Disclosure Project (CDP). 26 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Social Performance As a preferred partner for sustainable solutions, Trinseo is contributing to the well-being and quality of life of its employees and to improving the communities where it operates. As a part of this focus, Trinseo encourages its employees to make meaningful differences through volunteering and being active in their local communities. From an art center in Shanghai, a church in Indonesia, and homes for the elderly in Korea, to classrooms in Terneuzen, a career workshop in Sao Paulo, and an old-age home in India, Trinseo and its employees are making a positive difference. TOP Trinseo India employees and family members provided assistance to the elderly at an old age home, Shantikunj Sevashram. BOTTOM Trinseo employees in Schwalbach, Germany, organized a multipurpose event for approximately 250 homeless people in Frankfurt at the Diakonie community center. How May We Be of Service? Global Initiative Solidifies Commitment to Giving Back In May 2014, Trinseo launched a new community outreach program that encourages employees and their families to volunteer in support of the local communities in which they live and work. The global program, named DAYS Volunteer Days, was conceived as an annual event program involving Trinseo s 2,100 employees in 27 countries around the world. The program 2 0 1 4 was designed to formalize, expand, and connect the company s global volunteering activities while recognizing and raising awareness about volunteering. Under the program guidelines, Volunteer Days projects can be any activity for public benefit that ties to the Trinseo community relations themes of environment, improving the community, and education. To qualify, projects must be planned and completed in collaboration with an existing non-profit organization that has a mission related to these themes. The first Trinseo Volunteer Days held in May 2014 surpassed all expectations. More than 450 Trinseo employees in 11 countries volunteered for a total of 2,000 hours over 11 days the equivalent of 251 working days. Employees used the opportunity to donate their time, and in many cases money, where it was most needed. Locally formed volunteer committees used their creativity to come up with activities that were beneficial to the community, fun, and often challenging. Activities covered a broad spectrum from donating blood to cleaning up local parks. One group helped clear debris from a pet cemetery at a local animal shelter. Other groups assisted the elderly in need and taught lessons to school children. The largest event by far was held in Schwalbach, Germany, where Trinseo volunteers, who included four hairdressers, hosted an event for 250 homeless people. The event included haircuts, a luncheon with food provided by a local supermarket, and a clothing drive. TRINSEO VOLUNTEER 27 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Human Resources Performance Highlights Figure 15: Total Employees by Region Figure 18: Total Employees by Business Introduced a new learning and development strategy; identified a learning leader responsible for compliance, EH&S, and legal training; hired a Director of Talent Management to oversee all learning and development processes in the organization EMEA Latin America North America 1383 Asia Pacific 121 325 352 Leveraged 236 Services Basic Plastics & Feedstocks 479 441 Latex Rubber Performance Plastics 652 295 Made meaningful improvements in new global employee orientation/onboarding program Figure 16: Employee Breakdown Figure 19: Percentage of Represented Employees Developed a new brand to articulate HR s strategic goal to engage, develop, and reward employees Full Time Employees Part Time Employees 1911 83 Works Council 52.3 Representation Labor Party 13.1 Agreements Completed talent assessments and succession plans for senior-level leadership roles Temporary Employees Contractors 55 137 Unionized Employees 2.5 Non-represented 32.1 Key Facts Figure 17: Percentage of Workforce by Gender Figure 20: Percentage of Management 7 by Gender Employee Average Age: 44 Employee Turnover Rate : 3.1% Women 24.2 Women 9.9 Men 75.8 Men 89.1 7 Management is defined as the group of employees consisting of senior supervisory staff and executives in charge of detailed running of an organization or business/functional area. 28 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Coming Together to Make a Difference Annual Campaign Demonstrates Commitment to Giving Back Partnering with the United Way for the last five years has allowed Trinseo to demonstrate strong support for the communities where our U.S. operations are located. The United Way Giving Campaign is an annual, company-wide initiative that strengthens communities by assisting those in need, while bringing together our diverse employees around a single goal being a good neighbor. In 2014, our Global Operating Center located in Berwyn, PA, raised more than $43,000, and 74 percent of employees contributed. Together, over the last five years, the four U.S. operations sites have raised more than $268,000. The Art of Giving Back As part of the Trinseo global community outreach program, Volunteer Days, the company s Shanghai site was awarded the Outstanding Volunteer Award for Enterprise 2014 from Helin Art in Community in recognition of the company s contributions in natural art education. The award was presented at the inaugural ceremony of the Natural Art Education Program in Shanghai. It symbolizes Trinseo s efforts to improve the local communities by making a meaningful difference. Fifteen colleagues from the Shanghai site met with students between the ages of eight and 10 to teach them about natural art. In addition to the lessons they taught, the Shanghai employees also raised RMB 6,500 (approximately $1,000 U.S.) to purchase books and stationery for the children s continued education. Trinseo Berwyn, PA, employees wrapped up their United Way Giving Campaign with a Halloween party. 29 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Plastics Make It Possible RV visits Trinseo s Berwyn, PA, offices to explain recycling processes and efforts. One Man s Trash Is Another Man s T-shirt Don t Be Trashy. Recycle, was the tagline and message of the Plastics Make It Possible U.S.-based national tour highlighting the opportunities consumers have to recycle plastics every day. The tour s signature ride was a brightly colored, recycle theme recreational vehicle that housed educational activities. The Trinseo Global Operating Center, located in Berwyn, PA, was an official tour stop. Trinseo employees and community members were invited to take a peek inside the recycling process of plastic bottles and caps through an onboard reenactment of the actual process. At the end of the tour, visitors received an ultra-soft T-shirt made from recycled plastics. Plant Tour Sparks Positive Reactions After the Trinseo Guaruja, Brazil, latex plant received recognition for its best-in-class technology and zero environmental emissions, University of Santa Cecilia professor Eleni Stark asked plant employees to arrange a tour for her chemical engineering students. Every year since, Stark returns with a new group of 15 to 20 students that gain realworld engineering experience inside a chemical plant. Most recently, Stark s 17 students had an opportunity to observe general housekeeping tasks, such as how equipment and materials are labeled for risk control. They also toured technical areas of the plant, including the quality lab and process control room. Allowing students to step outside of the classroom also reinforces the importance of safety and Responsible Care. American Chemistry Council, Inc. All rights reserved. Responsible Care is a registered service mark of the American Chemistry Council in the United States. 30 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Spreading the Wings of Sustainability Wildlife Enhancement Effort Makes Sustainability Fly at Dalton Plant Chemical plants are easily recognizable by their industrial architecture, but the Trinseo site in Dalton, GA, shatters that notion with 300 acres of property dedicated to wildlife conservation and research. For nearly 17 years, the Dalton site has participated in the Wildlife Habitat Enhancement Program through the Wildlife Habitat Council. Nearly 30 percent of the site s employees are involved in maintaining the 300-plus acre property and executing various projects to demonstrate their commitment to the surrounding area. One of the site s largest ongoing wildlife projects is the provision and maintenance of nearly 40 bird boxes and four wood duck boxes, which increase nesting areas for the native birds. To prepare for the season, Dalton site volunteers receive training on how to identify the different birds in the area. Since the birds often leave their boxes when the volunteers go on-site each week, the volunteers have to look for other identifying factors, such as what materials the bird used to build the nest and the unique characteristics of eggs. At the close of the season, the volunteers report their data to the Cornell Lab of Ornithology a world leader in the study and conservation of birds. Data includes the number of active boxes, if there were eggs in the nests, how far along the eggs were, and what kind of birds were in the area. The team s long-term dedication to this project is an example of how Trinseo employees live and breathe sustainability and remain committed to support the local communities where they live and work. ABOVE Trinseo employees and their children work on a project to build an additional 15 nesting boxes to add habitat on site. RIGHT The first Eastern Bluebird eggs of the season. 31 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

SUSTAINABLE OPERATIONS Trinseo continually develops new ways to improve operations, products, and sustainability efforts by analyzing and enhancing our quality processes. We also have rigorous product safety programs, supporting regulatory compliance measures and leading the way in product stewardship with our customers. 32 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Quality Total Quality Policy Quality performance is a commitment to excellence by each Trinseo employee. It is achieved by teamwork and a process of continuous improvement. Trinseo is dedicated to being the leader in providing quality products and services that meet or exceed the expectations of our customers. Our quality philosophy focuses on delivering superior quality by first managing the manufacturing process to produce products to specific targets; this, in turn, assures that product specifications are met or exceeded. To accomplish this, Trinseo utilizes a modified Total Quality Management approach to assure and improve the quality of the company s products and services, thereby increasing customer satisfaction. The Trinseo quality approach is based on the idea that every person in the company has responsibility for and contributes to the quality of Trinseo s products and services. In fact, the strategies and performance metrics for Trinseo businesses include quality goals. Cross-functional teams involving employees with many different responsibilities (including business, research and development, purchasing, supply chain, manufacturing, etc.) are responsible for accomplishing these goals. By establishing a quality management system, Trinseo leverages the engagement of executive leadership, line management, and many functions within the workforce, as well as suppliers and customers, in order to meet and exceed customer expectations. Quality in Action To consistently meet established specifications and contractual obligations, as well as comply with regulations, Trinseo uses business performance standards in implementing its quality strategy. These standards emphasize a strategy to: Deliver products to customers within the agreed time (On Time) Deliver to customers the appropriate equipment, in clean and serviceable conditions, and accompanied by all expected, accurate paperwork (In Full) Deliver the right product and meet all agreed product quality and performance requirements (In Quality) Perform a proper analysis on all customer feedback to define corrective and preventive measures to minimize recurrence Measure performance against defined criteria and goals The Trinseo management system integrates the key elements of several external standards into its best practices, including ISO 9001 (standard quality management system), ISO 14001 (environmental health and safety), and cgmp (current Good Manufacturing Practices) for direct and indirect food-contact and medical products. Furthermore, Trinseo incorporates ISO/TS 16949 automotive quality management standards, which include best practices for design, development, production, installation, and servicing automotive products. Six Trinseo plants that produce dedicated products for the automotive industry are ISO/TS 16949 qualified. Trinseo s overall goal is to maintain a laser-like focus on meeting its customers needs every day and reliably providing quality products and services in order to earn and maintain their business. 33 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

ISO 14001 ISO 14001 is a generic, voluntary framework designed by the International Organization for Standardization to assist in developing individualized environmental management systems. It is based on the idea of continual improvement. Trinseo has developed and implemented an ISO 14001 compliant environmental management system, which was evaluated and certified by independent auditors when Trinseo was part of The Dow Chemical Company. As of the end of 2014, 58 percent of Trinseo plants and facilities were ISO 14001 certified. Act Check Plan Do ISO 50001 With completion of an external audit by Lloyd s Register Quality Assurance in May 2013 at the Böhlen and Schkopau sites, Trinseo Deutschland GmbH achieved a combined ISO 14001 and ISO 50001 recertification. (Initial ISO 50001 certification was achieved in June 2012.) During this successful recertification audit, the effectiveness of the Environmental and Energy Management System (EnMS) was assessed. In addition to Trinseo Deutschland and GmbH (Böhlen and Schkopau), all of the other Trinseo locations in Germany Stade, Rheinmünster, and Schwalbach are ISO 14001 and ISO 50001 certified. At the Schkopau and Böhlen sites alone, the use of the Environmental and Energy Management System will enable Trinseo to reduce power consumption by about three gigawatt-hours in each year starting in 2015. That is enough energy to power a village with a population of approximately 2,000 people for a year. We are leveraging our experience with ISO 50001 in Germany with other Trinseo locations around the world to capitalize on additional savings from energy efficiency. Percent of Trinseo sites with ISO 50001 certification 58% Percent of Trinseo plants with ISO 14001 certification 27% 34 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Suppliers As a Responsible Care company, Trinseo recognizes the importance of selecting suppliers based upon their commitment to sustainability, quality, Responsible Care, codes of conduct, and regulatory compliance. Trinseo continually updates its vendor selection criteria for raw materials and logistics suppliers to include these components. Trinseo is committed to purchasing from Responsible Care companies whenever possible, and we require suppliers to comply with our Supplier Code of Conduct. In 2013, Trinseo began developing a purchasing scorecard that evaluates suppliers on a wide range of criteria including quality, cost, and sustainability. Metrics in the sustainability category include hazard awareness training, ongoing tracking of EH&S performance, and the use of third-party environmental management programs such as ISO or Responsible Care. Trinseo began utilizing this scorecard with a select number of critical raw material suppliers during 2013. In 2014, Trinseo began developing a comprehensive Supplier Code of Conduct. This was introduced to Trinseo s raw materials suppliers in early 2015. Trinseo also recently issued a statement on Conflict Minerals and a commitment to the California Transparency in Supply Chains Act, which addresses human trafficking and labor rights. Eco-profiles and Life Cycle Analyses In order to determine the potential environmental impact associated with various plastics materials, it is important to collect and analyze data from multiple sources so that an accurate eco-profile of each material can be created. Trinseo contributed to the creation of eco-profiles for plastic products in both Europe and North America to help the downstream industries make well-informed product decisions. Beginning in 1990, the Association of Plastics Manufacturers in Europe (now PlasticsEurope) pioneered the first eco-profiles for virtually all types of plastics materials. The Trinseo businesses played a key role in collecting and contributing cradle-to-gate data for its polystyrene and polycarbonate resins. Energy and raw materials used, water consumption, emissions, and waste are just some of the variables analyzed to create each eco-profile. FABRICATION End Product Packaging Distribution Product Safety Trinseo is committed to understanding the impact of our products throughout their life cycles and providing straightforward communication about our products and their safe use. We work closely with industry trade associations to ensure that our products and their raw materials are appropriately classified for their hazards. Trinseo also supports ongoing toxicological testing to expand our understanding of chemical hazards. To further enhance understanding of the impact of our products throughout their life cycles, Trinseo contributes to developing eco-profiles, also known as Life Cycle Analyses (LCAs). PRODUCTION EXTRACTION Manufacture Plastic Resin Monomer Processing Raw Materials Acquisition Plastics Product LIFE CYCLE Recycling Energy Recovery Reuse Landfill USE END OF LIFE Responsible Care is a registered service mark of the American Chemistry Council in the United States. 35 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

In 1999, Trinseo s Latex business supported the creation of eco-profiles in the production of latex polymer dispersions in association with the European Polymer Dispersion and Latex Association (a sector group of the European Chemical Industry Council, or Cefic). An updated eco-profile was released in 2012. More recently, Trinseo was instrumental in the establishment of cradleto-gate life cycle inventories for The Plastics Division of the American Chemistry Council. Table 2: Eco-profile/Life Cycle Analysis Product Organization Year Polycarbonate PlasticsEurope 2010 Bisphenol A PlasticsEurope 2010 ABS PlasticsEurope 2005 Product Safety Process and Program Safety Data Sheets can be found on the Trinseo website or by calling the Trinseo Customer Information Group at +1-855-TRINSEO. Additional global phone numbers are available online. Through its comprehensive approach, Trinseo evaluates the safety of its products and strives to manage them in a safe and sustainable manner so that any potential adverse impacts on society or our environment are minimized. The foundation of our product safety activities is identifying and understanding the potential hazards, exposures, and risks that may be associated with the products Trinseo purchases, manufactures, and brings to market. This understanding is based on the following process steps: Figure 21: Product Safety Process SAN PlasticsEurope 2005 Polystyrene (GPPS) PlasticsEurope 2012 Polystyrene (HIPS) PlasticsEurope 2012 SB Latex EPDLA 2012 SA Latex EPDLA 2012 Styrene PlasticsEurope 2005 Polybutadiene PlasticsEurope 2005 STEP 1 Gather existing scientific information about the potential hazards of our products. Determine likely levels of exposure by considering factors such as product composition, manufacturing practices, applications, etc. STEP 2 STEP 3 STEP 4 Revisit the product safety process periodically to review best practices and to identify any information gaps that may exist. Develop new information should gaps be identified. Evaluate risks (Risk = Hazard x Exposure) to human health and the environment. Take steps to manage and/or reduce risks appropriately. STEP 5 STEP 6 Document conclusions. 36 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Regulatory Compliance Once this foundation is established, Trinseo integrates the information and product safety practices into a wide range of activities as elements of Trinseo s product safety program. The elements of the Trinseo product safety program include: Community outreach and awareness Distribution and logistics EH&S training Emergency preparedness and response Employee health and safety Engineering and design for environment, health, and safety Industrial hygiene Occupational safety Operating design and management Product stewardship Security Third-party services The Trinseo product safety program is designed to make sure that its products are made, stored, transported, used, disposed of, and recycled sustainably and in a way that demonstrates world-class practices of safety, environmental stewardship, and regard for people. This commitment is embodied in the Trinseo EH&S Policy. Trinseo encourages its suppliers and customers to join its efforts to collaborate, innovate, and elevate industrial practices and expectations so that chemical products are managed safely throughout their life cycles. Consistent with the Trinseo EH&S Policy, Trinseo supports the development of laws, regulations, procedures, and operating practices that are science-based and safeguard workers, plant communities, customers, and the environment. To facilitate this commitment, Trinseo has implemented a comprehensive approach for monitoring and complying with relevant industry standards and government regulations globally. This approach includes the use of internal expertise, third-party consultants, regulatory databases, and industry associations to: Develop and adhere to internal standards that ensure Trinseo s products can be produced and sold globally while also complying with local requirements Monitor and document compliance to existing regulations and industry standards Implement compliance approaches for newly enacted regulations Identify emerging regulations and industry trends As stated in Trinseo s EH&S Policy, Health, safety, and protection of the environment are Core Values which are a part of everything we do. Our focus on these Core Values, which include regulatory compliance, provides assurance that our products can be used safely in intended applications across the world, including sensitive end uses such as food contact and medical applications. Trinseo has dedicated significant resources to European regulatory compliance with a particular focus on EU REACH. 37 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

EU REACH Trinseo remains vigilant in its efforts to comply with global chemical laws, such as REACH (Registration, Evaluation and Authorization of Chemicals). REACH is the single regulatory system for chemicals management in the European Union (EU). REACH requires that EU manufacturers and importers of substances to the EU (starting with quantities of one metric ton per year) disclose information on the properties of their substances, including the risk to humans and the environment associated with use. Information on appropriate risk reduction measures must also be provided. Trinseo recognizes and fulfills the EU REACH registration requirements for the relevant substances it manufactures in (or imports into) Europe. In addition, Trinseo remains engaged in addressing the registration requirements for purchased substances by engaging in direct discussions with SIEFs, consortia, and direct suppliers. Trinseo conducts downstream use assessments and utilizes the exposure scenarios associated with substance registrations to ensure our operational activities are REACH compliant. Trinseo fully supports the objectives of REACH and the responsibility the legislation places on all members of the value chain to manage the safe use of chemicals. We believe it represents a significant opportunity for chemical manufacturers, their suppliers, and customers to work together to protect the environment and preserve the future of the chemicals industry in Europe. As other nations consider similar regulations devoted to chemicals management, Trinseo will support these efforts and implement appropriate compliance solutions. Trinseo is duly fulfilling its obligations resulting from the publication of the ECHA Candidate List for Authorization. Information on Trinseo products containing substances on the Candidate List (SVHCs) above reportable limits can be found in the Safety Data Sheets. Trinseo proactively sends these updated data sheets to all customers currently purchasing concerned products. EU REACH Next Steps In line with REACH and other regulations, Trinseo will now focus on updating the relevant European Safety Data Sheets with REACH registration numbers and where required with annexes on use and exposure scenarios. With further implementation milestones through 2018, Trinseo will remain actively involved in industry trade associations working on REACH. For further information about REACH, visit the website for PlasticsEurope, www.plasticseurope.org, and select REACH under the Plastics & Sustainability menu. 38 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Trinseo Maintains Responsible Care Certification In August 2013, Trinseo successfully passed its Responsible Care Management System audit and continues to use the designation of a Responsible Care company on a global basis. To maintain the voluntary certification which is above and beyond what is legally required in most countries an audit is administered every three years by a third-party auditor approved by the American Chemistry Council. The audit focused heavily on operating discipline management systems, policies, and chain of authority. In Trinseo s case, the auditor also looked closely at how Trinseo accesses systems, tools, and standards from Dow as part of our service agreements. In comparison to other companies, Trinseo was recognized for strengths including: Outstanding plant housekeeping especially for a top-tier chemical company Detailed and practical site emergency plans Comprehensive and best-in-class product stewardship programs Pleased with the results of the audit, Trinseo also moved quickly to address the recommended areas of improvement. EH&S Audits As part of its commitment to sustainability, Trinseo conducts audits of its manufacturing and research and development facilities every three to five years. The purpose of these audits is to verify the status of Trinseo facilities with respect to meeting external authority and internal company environmental, health, and safety criteria. Trinseo retains Enhesa, a global environmental, health, and safety (EHS) consultancy that provides industry-wide, regulatory compliance assurance support to perform these audits. Audit teams are composed of Trinseo experts in various disciplines such as environmental, personal safety, process equipment safety, transportation, security, and management systems. Trinseo Manufacturing Sites Receive Safety Award Three Manufacturing Sites Meet ACC Top-tier Safety Performance Requirements Trinseo s safety performance is built on a culture whose focus on safety extends from senior leadership to shift workers. In 2014, three Trinseo manufacturing sites all latex plants in the U.S., which includes Dalton, GA, Allyn s Point, CT, and Midland, MI received the Responsible Care Facility Safety Award from the ACC for having met top-tier safety performance. The award is presented to member companies based on achievements in employee health and safety performance. Trinseo received the Certificate of Excellence, which is the highest safety award offered by the ACC. It requires company manufacturing facilities to achieve zero days away from work and zero restricted work cases for both company employees and contractors. Responsible Care is a registered service mark of the American Chemistry Council in the United States. 39 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Operational Efficiencies Germany Plant Recovers Hydrogen, Reduces Waste Employees at the Trinseo Styrene Manufacturing plant in Böhlen, Germany, implemented a project to improve energy efficiency and reduce waste. In the production of styrene, one of the reactions results in the formation of hydrogen, which is either recycled or disposed of. There are two options to dispose of hydrogen: combustion (burning with no energy recovery) or burning, recovering, and reusing some of the resulting energy. In 2013, the Böhlen plant employees modified the main burners to allow the burning of hydrogen vent gas as a fuel in the cracking furnaces. The recycled hydrogen vent gas was used in place of natural gas to power the process furnace. This resulted in a significant decrease in the amount of primary energy (natural gas) used at the plant, and a decrease in CO 2 emissions. In 2014, the plant decreased natural gas consumption by 2,337,000 kg, enough energy to meet the winter heating needs of 850 U.S. homes. hydrogen 1 H1.0079 2,337,000 kg = energy 850 equivalent to heat 850 homes Trinseo Receives First Leaf Award In 2013, Trinseo joined Green Freight Europe (GFE), an industry-led initiative focused on reducing carbon emissions from road freight in Europe. GFE encourages member companies to measure and reduce CO 2 emissions from transport operations, and share results. In 2014, Trinseo became one of 20 companies to be awarded with the GFE first leaf an award given to companies that have shared CO 2 data and information on policies, strategies, and intentions to reduce CO 2 emissions stemming from freight operations in Europe. The first leaf is part of a four-tier labeling program by GFE that recognizes and benchmarks members based on their efforts and measures to further improve on CO 2 reduction. In 2014, for the Trinseo European Plastics business, intermodal transportation was 44 percent of total volume versus conventional road transportation. With intermodal transportation, the major transport is done by rail-or sea-based vehicles. Generally, rail and sea transportation is more carbon-efficient than road transportation. From lightweighting products to payload optimizations, Trinseo is working to drive sustainable transportation. Receiving the first leaf designation is another example of Trinseo s desire and ability to do more with less and achieve more sustainable results. 40 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

OUR COMMITMENTS Trinseo s commitment to our customers, suppliers, communities, and employees is exhibited through exceptional quality, industry-lead safety, and the highest integrity. Our Core Values, Environmental Health & Safety Policy, support of Responsible Care, and Ethics and Compliance Policy guide our endeavors to ensure exceptional and sustainable performance. Responsible Care is a registered service mark of the American Chemistry Council in the United States. 41 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Core Values Environmental, Health, and Safety Policy * Responsible Care As a Responsible Care company, the health and safety of our employees and the protection of our communities are our highest priorities. We strive for meeting or exceeding the highest standards of environmental and safety performance. Respect and Integrity We treat each other, our customers, and our stakeholders with respect and dignity. We conduct all business activities with the highest ethical standards and are fully committed to comply with the law everywhere we operate. Accountability and Value Creation We believe that speed and agility combine with good decision-making to create value. We feel ownership and take accountability for our company s success. Innovation We believe that innovation through our technology and the creativity of our people powers our success and the success of our customers. Commitment to Customers By collaborating with our customers, we deliver value through our technology, innovation, and solutions. At Trinseo, we conduct our business of providing innovative solutions and superior materials with integrity and care for our colleagues, communities, customers, and the environment. Health, safety, and protection of the environment are Core Values, which are a part of everything we do. We are committed to the continuous and measurable improvement of our environmental, health, and safety performance. We are committed to minimizing any potentially harmful impacts of our products throughout all stages of their life cycles by promoting the responsible use of our materials throughout the value chain. Our goals include eliminating workplace injuries and illnesses, preventing adverse environmental impacts, reducing and preventing waste and emissions, and promoting resource conservation at every stage of the life cycle of our products. We are fully committed to compliance with environmental, health, and safety (EH&S) laws and regulations and with internal EH&S policies and standards that support our Core Values. Trinseo will devote adequate resources, training, standards, and procedures to satisfy this policy. Every employee and contractor is responsible for compliance with these principles and this policy. We will audit and continually improve our performance, and the executive leadership team and the EH&S committee of the board of directors will monitor our commitments and progress. *Adopted by Trinseo January 2011 Responsible Care is a registered service mark of the American Chemistry Council in the United States. 42 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Responsible Care Trinseo is proud to participate in the chemical industry s Responsible Care initiative. In November 2010, Trinseo officially endorsed Responsible Care and pledged to operate the company according to its guiding principles globally. Responsible Care is a voluntary initiative of the global chemical industry to safely handle our products from inception in the research laboratory, through manufacture and distribution, to ultimate reuse, recycle, and disposal, and to involve the public in our decision-making processes. Developed in Canada in 1987, Responsible Care quickly spread to 53 countries. While Responsible Care goes above and beyond what is legally required in most countries, we hold ourselves accountable by making Responsible Care a condition of membership in industry associations. Trinseo uses the Responsible Care management system framework and reported the results of the first formal review of its efforts to implement Responsible Care in August 2013. Trinseo has implemented the following Responsible Care principles: To lead our companies in ethical ways that increasingly benefit society, the economy, and the environment To design and develop products that can be manufactured, transported, used, and disposed of or recycled safely To work with customers, carriers, suppliers, distributors, and contractors to foster the safe and secure use, transport, and disposal of chemicals, and provide hazard and risk information that can be accessed and applied in their operations and products To design and operate our facilities in a safe, secure, and environmentally sound manner To instill a culture throughout all levels of our organization to continually identify, reduce, and manage process safety risks To promote pollution prevention, minimization of waste, and conservation of energy and other critical resources at every stage of the life cycle of our products To cooperate with governments at all levels and organizations in the development of effective and efficient safety, health, environmental, and security laws, regulations, and standards To support education and research on the health, safety, environmental effects, and security of our products and processes To communicate product, service, and process risks to our stakeholders and listen to and consider their perspectives To make continual progress toward our goal of no accidents, injuries, or harm to human health and the environment from our products and operations and openly report our health, safety, environmental, and security performance To seek continual improvement in our integrated Responsible Care management system to address environmental, health, safety, and security performance To promote Responsible Care by encouraging and assisting others to adhere to these guiding principles Responsible Care is a registered service mark of the American Chemistry Council in the United States. 43 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Ethics and Compliance Ethics and Compliance Policy It is the policy of Trinseo to be lawful, high-principled, and socially responsible in all of its business practices. We expect our employees to learn and comply with all corporate policies and laws applicable to their job responsibilities as outlined in the Trinseo Code of Business Conduct and supporting policies. All Trinseo employees, officers, and directors must share Trinseo s commitment to ethical business conduct. The Trinseo Ethics and Compliance program and standards apply to all employees in all regions. Trinseo s activities related to ethics and compliance are overseen by the chief compliance officer, who also chairs Trinseo s ethics and compliance committee. The chief compliance officer is responsible for the oversight and management of the Ethics and Compliance program, which is comprised of nine senior Trinseo executives representing diverse functions and geographies. The Ethics and Compliance Committee reviews, modifies, and updates the Code of Business Conduct and its supporting policies on an ongoing basis. The Committee also oversees the responses to any ethics or compliance reports or questions, conducts or monitors any investigatory activity, and assists in communicating the ethics and compliance program to Trinseo s employees and the public. Trinseo has a rigorous reporting program for ethics and compliance issues that includes an expectation that employees speak up and report any issues. We have contracted with a third party to provide an ethics and compliance hotline, which allows anonymous reporting of ethics and compliance concerns or allegations where legally possible. Trinseo s web-based ethics and compliance training module is available in 10 languages, and nearly 95 percent of employees have completed the training as of December 2014. 95% Percent of Trinseo employees who completed ethics and compliance training 44 TABLE OF CONTENTS SUSTAINABLE PRODUCTS

Social Media Efforts Expanded In 2014, we expanded our social media efforts which include Facebook, LinkedIn, Twitter, and YouTube. Building closer relationships with employees, media, suppliers, distributors, and those living in the communities in which we live and operate is important. Updates on trade shows and conferences, new products, awards, company happenings, and participation at community events are examples of information found on our various social media platforms. Connect with us! About This Report The Trinseo Corporate Responsibility and Sustainability Report contains information on the company s performance in the following areas: environment, social, safety, product stewardship, and financial results. Our goal is to communicate our business strategy of sustainable growth and demonstrate that since its formation in June 2010, the company has focused on continuous improvement in all areas of its operations. This report reflects company efforts during the 2014 calendar year. Previous reports reflected performance for Trinseo during the 2011, 2012, and 2013 calendar years. Report boundaries and measurement methods are similar in all reports. We also respond throughout the year to direct requests from environmental, social, and governance research agencies, individual shareholders, non-governmental organizations, academic institutions, customers, and individual students regarding the company s environment, health and safety, and social responsibility policies, programs, and performance. This report and additional information can be found at www.trinseo.com. For more information on products, innovations, expertise, and other services available from Trinseo, visit www.trinseo.com, or contact us as indicated below. North America U.S. & Canada +1-855-TRINSEO (+1-855-874-6736) +1-989-633-1718 Latin America Brazil +55-11-5184-8722 Argentina, Chile, South +54-11-4319-0100 Region of LAA Mexico, Colombia, North +52-55-5201-4700 Region of LAA Europe/Middle East/Africa +800-444-11-444 +31-11567-2601 Asia Pacific +603-7965-53-19 China +86-21-3851-1017 www.trinseo.com Copyright Trinseo (2015) All rights reserved. Trademark of Trinseo S.A. or its affiliates Formerly known as Styron, Trinseo completed its renaming process in the first quarter of 2015. Form No. 845-1301-0615 SMG 12903