NTU Chemical Spill Guideline 1. Scope This guideline is for the handling of hazardous solids and liquid spills. It does not cover high risk unintentional release involving : a) any gaseous chemicals; b) highly reactive material; c) radioactive material; or d) explosive material. Each laboratory or other work area that use such substances should have specific spill procedures for these substances (both storage and use). 2. Rules & Responsibilities Workplaces where chemical or biological substances are stored or used (either as new or waste), Principal Investigators (PI), Laboratory Managers (LM) & Supervisors should ensure that spill management is in place as follows: availability of spill containment equipment or kit; safety information (SDS) of the hazardous substance; appropriate Personnel Protective Equipment (PPE) for spill management; ensure training to be provided; and safe disposal of spilled material. 3. Definition Spill - Any unintended release of any substance at the workplace. Hazardous Substance - Any substance that may potentially cause harm to the user himself, another person, or endangering the environment. Emergency - Any situation which is unclear to the person causing or discovering the spill, that: requires the mass evacuation of all persons ; may cause fire or explosion ; result in high exposure levels of hazardous substances ; and/or may not be able to handle by himself. 4. Risk Assessment When a new substance is brought into the workplace, the PI (primary contact person) or in his absence, the LM (secondary contact person) shall carry out a risk assessment for the spill control of the hazardous material (substance). The risk assessment is to include: The nature of the spilled substance (hazard and risk) ; The quantity spilled (large/small amount) ; The location of the spill (difficult access, public area / restricted area) ; Special training required to handle the situation including PPE; and Special procedures required cleaning up the spill e.g. use of special detergent or use of a diluents.
5. Size of Spill A spill in the workplace can be: Type Amount Exceptions Persons for spill Minor < 5 litres liquid < 5 kg solids Major >5 litres liquid > 5 kg solids Not for very toxic, Highly Flammable or highly reactive substances Highly Toxic, Flammable reactive substances inclusive Use of Call SCDF ERT 1 No Only if situation is out of control and/or public is in danger. 2 Only if situation is out of control and/or public is in danger. 6. Chemical Spill Management The steps for spill management are shown in the left hand side of Figure 1 (in blue). 7. Acid / Alkali spill 7.1 Spills of acids/alkali (except HF) can either absorbed using inert absorbents (preferred method) or neutralized. (Note: For concentrated acids, dilute the absorbed acid with equal amount of water.) All absorbed and neutralised substances shall be disposed of via licensed waste collectors. 7.2 Acid spills can be neutralized with sodium bicarbonate. 7.2.1 Contain the liquid spill first. 7.2.2 Sprinkle power over the spill slowly, starting from outside. 7.2.3 Test with ph strips (ph 6-8). 7.2.4 Acid is neutralized if effervescence ceases in the presence of excess bicarbonate. 7.2.5 Avoid breathing in fine powder and the gas evolved (carbon dioxide). 7.3 Alkali spill can be neutralized with either boric acid or oxalic acid as described in 7.2.1 7.2.3 above.(note property of neutralizing acids). 7.4 Do not mix strong acids and alkali together as neutralizing agents. 8. Special Spill 8.1 Mercury Note: Mercury vapour is toxic. 8.1.1 Evacuate immediate area (minimum an exclusion radius of 3m). 8.1.2 Use gloves and chemical respirator (half mask with dual filter cartridge). Use shoe covers if possible. 8.1.3 Gently (a) suck up with a disposable pipette; or (b) sweep up using a hard plastic scrapper and pan.
(Note: Pick up sharps if any with tongs/tweezers). 8.1.4 Use a LED torch light to look for mercury droplets trapped in surfaces such as table cracks or tiles grout. 8.1.5 Sprinkle sulfur powder liberally to cover spilled area. Wait for 30 minutes. Sweep up all powder and place in a plastic container for disposal. 8.1.6 Wipe area down with copious amount of water and detergent. 8.1.7 Check area again for any mercury using torch light. 8.2 Hydrofluoric Acid (HF) For HF Spill, make sure you are well protected especially against any skin surface contact. HF must be treated before disposal. 8.2.1 Contain spill first. 8.2.2 Sprinkle Calcium Chloride or Carbonate powder liberally on the spill till excess powder is seen, starting from the external of the spill. 8.2.3 Allow 1 hour to react. 8.2.4 Sweep up powder or liquids. Bag and dispose of via licensed waste contractor. 8.2.5 Avoid direct surface contact with spilled material. 9. Recommended Spill Kit Please refer to Appendix 2. 10. Biological Spills in a contained environment Spills that are contained (i.e. in Biological Safety Cabinet, centrifuges, etc.) are not as dangerous since they are already confined to a small area. Nonetheless, care must be taken to ensure the spill remains confined and that equipment is not contaminated. The possibility of aerosol generation must also be evaluated as this will impact the risk of exposure and degree of contamination resulting from the setting or aerosols or droplets. 10.1 Spills within a biological safety cabinet (BSC) 10.1.1 Leave the ventilation on. 10.1.2 All items within the cabinet should be disinfected (Walls and surfaces wiped down, equipment wiped down and/or autoclaved before disposal). 10.1.3 Cover the spill area with paper towels. 10.1.4 Pick up with paper towels (with gloved hands or thongs). 10.1.5 All waste should be autoclaved. 10.1.6 Ventilation should run 10-15 minutes. 10.1.7 Clean the spill area with an appropriate disinfectant (i.e. 10% clorax or 70% IPA/Water). 10.2 Spills within a centrifuge 10.2.1 Leave lid closed and allow aerosols to settle for at least 0.5 hour (ensure centrifuge is off). 10.2.2 Notify others in the lab not to use the centrifuge (use warning signs) and inform LM or PI.
10.2.3 If possible, move the centrifuge (or at least the rotors and buckets) to a BSC. 10.2.4 Disinfect the centrifuge or rotors and buckets using an appropriate disinfectant, allow at least 30 minutes of contact time. 10.2.5 Carefully retrieve and broken glass from inside the centrifuge using forceps/tweeters and place in a sharps container. 11. De-contamination Tools and PPE All tools (plastic scoop, tongs, etc) used in the clean up need to be washed with copious amount of water. Dry the tools and place them back into the spill kit along with the splash goggles. Replace chemical cartridges as necessary and disinfect respirator.. Dispose of the gloves, N95 mask and protective suit. Replenish the spill kit. Wash hands and face thoroughly Change laboratory coat immediately after decontamination. If hair is contaminated, wash immediately. Wipe the sole of the shoes (or dispose of shoe covers). No person with open toe shoes or slippers must handle spills.
Appendix 1: Additional Information 12. Liquid Spills (Other than flammable liquids) Spread the absorbent pads over the spill starting with the edges first. This will help to contain the spill to a smaller area. (Do not step ON adsorbent pads/pillows) Spread enough pads over the spill to completely cover the liquid. Pick up the contaminated pads with tongs or scoop and place into double polyethylene bag. If chemical is water soluble, wipe the area down with a paper towel, followed by wet mop and detergent. Dispose of paper towel with the waste generated from the spill cleanup. Seal bag with bag ties. 13. Flammable Liquids Spills Control all sources of ignition turn off all electrical apparatus and heat generating equipment. Spread the pads over the spill, starting from the edge. Allow pads to completely soak up liquid. Pick up pads with tongs or scoops; minimize direct contact. Place in polyethylene bag. Wipe the area down. Seal bag with bag ties into an air tight container if possible. Never use wet vacuum cleaner directly on flammable solvents. Wipe with detergent and water. 14. Solid Spills Use the plastic scoop to place the spilled material into the polyethylene bag. Care should be taken so as to minimize raising of dust or cause the contaminated powder to become airborne. Use of a dust mask would be advisable. After the bulk of the material is cleaned up, wet a spill pad and wipe the area down. Place the pads into the polyethylene bag. Wipe the area down with a wet paper towel. Dispose of paper towel with the waste generated from the spill clean-up. Seal bag. 15. Odorous Chemicals Immediately cover the area with several pads if necessary a soaked pad to minimize odours from spreading and vapourising. Use booms to contain the spills. Immediately call for help. Use respiratory protection with an appropriate cartridge filter. Do not use paper or fiber masks. Depending on the amount and area of spill, the air-condition may be shut down, windows opened and the air in the immediate area evacuated using an exhaust fan with the outlet directed out of the window. Treat liquid as normal liquids spill (either flammable or non-flammable) Note: If material is lachyrmating, goggles or full respirator is to be used.
Appendix 2: Spill and PPE kit Minor Spill Major Spill Pad, Absorbent 4 8 Pillow, Absorbent 2 3 Sock, Absorbent 2 4 Pan / Brush + plastic scraper 1 set 1 set Broom / Spade -- 1set Tongs, plastic 1 1 Paper towels 1 pack 1 pack Tweezers, metal, angled, sharp 1 1 Plastic dropper (Mercury) Clear plastic bottle, (200ml) with tight fitting cap Reactants: --- 3 1 Acid Spill - Sodium Bicarbonate 5kg x 1 5kg x 2 Alkali Spill - Boric Acid/ oxalic acid 5kg x 1 5kg x 2 HF Spill - Calcium Chloride /Carbonate 3kg x 1 3kg x 2 Mercury Spill : Sulphur -- 1kg x1 PPE: Hand Protection: Gloves, nitrile 2 pairs (M, L) 4 pairs (M,L) Double gloved* Eye Protection: Goggles 1 pair 2 pairs Body Protection: Laboratory Coat 2 pairs, disposal Tyvek suits Respiratory Protection Half face, dual respirator, chemical N95 (biological and fines) One, M 2 pieces Two, M 4 pieces Foot Protection No open footwear Shoe covers ( 3 pairs) Spill kits should be restocked following use and the contents should be checked on a monthly basis
Appendix 3: Spill Prevention The best spill prevention is not to create a spill in the first instant. Majority of chemical spills can be prevented or minimized by: 1.1 Maintaining a neat and organized work areas. 1.2 Review procedure prior to compound; know your chemicals. 1.3 Storing liquid chemicals in secondary containment bins. 1.4 Keeping reagent chemical containers sealed or closed at all times, where possibility. 1.5 Order reagent chemicals in plastic or plastic shrink wrapped glass containers whenever possible. 1.6 Never store more than required as a guide sufficient for a week s supply or at the most four weeks used in open work area. 1.7 Transport chemicals bottles in appropriate carriers. 1.8 Carry chemicals properly. 1.9 Use an over bag or zip lock bags if necessary, especially for hazardous chemicals. 1.10 For transport outside NTU, all substances are preferably packed as per IATA regulations.
Figure 1: Spill Management Procedure SPILL QUICK ASSESSMENT Anymore Hurt? Attend to injured first. Seek Medical help if necessary STOP SPILL (only safe to do so) No Any Primary Hazards? (airborne) Note (1) FIRE: Highly Flammable Substance* BIOLOGICAL: (High Risk Group) 3 or 4 TOXIC: Highly Toxic *Remove all ignition sources within 3m Evacuate Spill Area Immediately Ventilate Area INFORM Others of Spill Can you handle spill? No Call for HELP (ERT or trained laboratory staff) Cordon Off Large >5l (liquids) / 5kg solids PPE Put on appropriate PPE Small <5l Note (2) Large >5l Note (3) Any Secondary Hazards? SHARPS Remove sharps with tools, decontaminate & dispose of No CLEAN UP (Note 4) DISPOSE OF Absorbed spill DECONTAMINATE AREA Remove cordon Stop ventilation DECONTAMINATE SELF CLEAN UP Dispose of gloves Check self if hurt Seek medical help No ADMINISTRATION incident report to OHS disposal by licenced contractor
Note: (1) Primary Hazards Hazards most likely to cause significant ill effects. ie. Fire or Poisoning (2) PPE recommend for small spill Hand Protection Gloves Eye protection Safety spectacles Body Protection Lab coat Respiratory Protection Cartridge respirator (if toxic) N95 (if fine solids) N95 for all biological (3) PPE recommended for large spill (2 persons recommended). Hand Protection Gloves (double gloves recommended) Eye Protection Goggles Respiratory Protection Cartridge respirator N95 for biological N95 (if fine solids) Body Protection Tyvik suits Apron (if strong acids/alkali) Foot Protection Wellington Boots or Shoe covers (4) Clean Up Chemical Liquids Soak up using absorbent pads Bag and label Waste disposal company Solids Sweep up gently Bag and label Waste disposal company Biological Liquids Soak with paper absorbent towels Autoclave Disposed of via waste disposal company. Acids use solid sodium bicarbonate of equal proportion Alkali use solid oxalic or boric acid of equal proportion Special Mercury, HF