Guidance document for the classification of dangerous goods with regard to their "corrosive effect on living tissue"

Transcription

1 Guidance document for the classification of dangerous goods with regard to their "corrosive effect on living tissue" Updated guidance document of the BfR published on 12 June 2012 This guidance document is intended to assistthe manufacturers of chemicals or chemical products when self-classifying of transport goods in Class 8 (corrosive substances) on the basis of the UN Recommendations on the Transport of Dangerous Goods (Model Regulations). The aim is to outline various options to facilitate in particular the classification of mixtures for which there are no calculation methods in the dangerous goods regulations. For this reason, calculation methods taken from the legislation governing chemical substances are used for the classification of mixtures with skin-corrosive ingredients. The guidance document describes the assessment practice of the Federal Institute for Risk Assessment (BfR) which, however, may differ on the base of expert judgement, i.e. in individual cases, substance specificities may result in an assessment that deviates from assessments for standard cases. The BfR is one of the institutions nominated as safety authority in the German Act on the Transport of Dangerous Goods (GGBefG). Pursuant to Art. 2(8) of the BfR Act the institute advises the Federal Ministry of Transport, Building and Urban Development (BMVBS), the Federal Ministry for the Environment, Nature Conservation and Reactor Safety (BMU) and the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV) on the assessment of the health risks of dangerous goods transport, risk prevention and emergency measures, in particular with regard to the transport of toxic and corrosive substances. 1 Necessity for classification of substances and mixtures on the basis of the legislation governing dangerous goods When transporting dangerous goods, clear classification based on the regulations governing dangerous goods is mandatory. If a substance or a mixture of substances with components in certain concentration limits is specified by a UN number and assigned to Class 8, the appropriate Packing Group can be identified from the substance list. The Packing Group corresponds to the hazard level of the transported goods. The sender is required to perform dangerous goods classification if: Classification with a selection of the Packing Group is possible The hazard potential of substances in the solution or mixture that are classified by name deviates from the hazard potential of the specified substance A substance with skin-corrosive properties is to be transported but does not yet have a UN number A mixture containing skin-corrosive substances is to be transported but does not yet have a UN number, An exemption from Class 8 is permitted in line with the definition principle Seite 1 von 8

2 2 Dangerous goods classification of substances and mixtures based on experimental data 2.1 Data from animal experiments In the simplest case, for the hazardous goods classification of substances and mixtures experimental data is available based on OECD Test Guideline 404 entitled Acute Dermal Irritation/Corrosion (2). This enables assignment to the three Packing Groups. The decisive factor is the exposure time after which complete destruction of the skin is observed in animal experiments (see Table 1). 2.2 Data from in vitro tests If no animal experiment has been conducted based on OECD Test Guideline 404 for a substance or mixture and no data is available that permits classification based on the legislation governing chemical substances and the application of the bridging principles, data from vitro tests may be used for the purpose of dangerous goods classification. It should be taken into account, however, that currently only the membrane model based on OECD Test Guideline In Vitro Membrane Barrier Test Method for Skin Corrosion (3) - permits subdivision into the three Packing Groups. This method is not suitable for all substances, however, and has not yet been validated for mixtures. The restrictions listed in the Test Guideline must be noted. In the case of doubt, a decision must be made by experts as to whether this in vitro test is suitable for the substance or mixture in question. The in vitro methods based on OECD test Guideline 430 In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER) (4) and OECD Test Guideline 431 In Vitro Skin Corrosion: Human Skin Model Test (5) are only recommended for classification in Category 1, CLP Regulation. At the current time, therefore, they may only be used to arrive at an initial assessment as to whether corrosive properties are at all present that require classification in dangerous goods Class 8. More recent evaluations suggest, however, that in vitro tests using human skin models (OECD Test Guideline 431) may permit sub categorisation of skincorrosive substances with a degree of reliability similar to that of the membrane model based on OECD Test Guideline 435. Until such time as Test Guideline 431 is updated, however, an expert opinion should be obtained before making a decision on which approach to adopt. In some cases, precautionary assignment to a stricter Packing Group may be a suitable means of avoiding animal experiments and taking account of existing scientific uncertainties. When making a choice between an animal experiment and differentiation between Packing Group II and Packing Group III, the general rule was that animal experiments should be avoided wherever possible and that results from alternative in vitro tests resulting in R34 status should lead to precautionary classification in Class 8, Packing Group II for the purpose of dangerous goods transport (see also 3.1 and 3.2). By way of analogy, positive results from alternative in vitro tests that do not permit differentiation between the subcategories 1B and 1C should in future lead to precautionary classification in Class 8, Packing Group II for the purpose of dangerous goods transport. 3 Dangerous goods classification of substances and mixtures based on classifications in line with the legislation on chemical substances Seite 2 von 8

3 3.1 Background As of Dec 1, 2010, chemicals (and from June 1, 2015 at the latest, mixtures of chemicals) must be categorised and labelled in line with Regulation No. EC/1272/2008 on the classification, labelling and packaging of substances and mixtures (CLP Regulation) (6). The CLP Regulation is based on the globally harmonised system for the classification of dangerous substances (GHS) (7). In the past, the classification of chemicals was governed by Directives 67/548/EEC (8) and 1999/45/EC (9) respectively by the regulations governing dangerous substances. Based on transitional provisions, it is mandatory for substances to be classified on the basis of both, the former legislation governing chemical substances and the new CLP Regulation in the period up to June 1, Based on the CLP Regulation, the category "skin-corrosive" is divided into three subcategories corresponding to the three Packing Groups of Class 8 for dangerous goods transport (see also Table 1): After a maximum exposure time of three minutes, a skin-corrosive effect must be determined within an observation period of one hour: Packing Group I or subcategory 1A After an exposure time between three minutes and one hour, a skin-corrosive effect must be determined within an observation period of 14 days: Packing Group II or subcategory 1B After an exposure time between one and four hours, a skin-corrosive effect must be determined within an observation period of 14 days: Packing Group III or subcategory 1C Hitherto the EU legislation on chemical substances comprised only two hazard classification categories: R34 - causes burns and R35 - causes severe burns, while there were three Packing Groups (see Table 1). Substances and mixtures classified as R35 were assigned to Packing Group I. Substances and mixtures classified as R34 were assigned to the relevant Packing Group based on further data - e.g. in vivo data for other relevant endpoints or data from in vitro trials. If no or only insufficient data was available for differentiation between Packing Groups II and III, Packing Group II was chosen as a precautionary measure. When the CLP Regulation was introduced, substances classified R34 were always assigned to subcategory 1B, while R35 substances were assigned to subcategory 1A. Seite 3 von 8

4 Table 1: Comparison of classification criteria for dangerous goods and chemicals with skin-corrosive properties, tested in line with OECD Test Guideline 404 Exposure 3 min >3 60 min > min Observation time 60 min 14 days 14 days Finding corrosive corrosive corrosive Dangerous good Model regulations Class 8 Packing Group I Class 8 Packing Group II Class 8 Packing Group III Dangerous substance EC 1272/2008 Skin-corrosive 1A Skin-corrosive 1B Skin-corrosive 1C Dangerous substance 67/548/EEC 3.2 Classification of substances Causes severe burns (R 35) Causes burns (R 34) Substances classified as skin-corrosive in Annex VI of the CLP Regulation can be assigned to the relevant Packing Groups. It should be noted, however, that the CLP Regulation currently contains no substances classified in line with subcategory 1C (see also 3.1). In future, producers and importers must classify substances in terms of their skin-corrosive properties themselves and must also derive specific concentration limits where applicable. These self-classifications are listed in the C&L Inventory Database on the ECHA homepage ( They may also be used as a basis for dangerous goods classification. It should be noted, however, that the entries in this database are not checked for accuracy. Information on skin-corrosive properties can also be obtained from the safety data sheets. 3.3 Classification of mixtures Concentrations above 1% of each ingredient classified as skin-corrosive under the legislation on chemical substances are added up. If the sum is greater than or equal to 5%, the mixture is classified according to the following rules (additivity approach): Table 2: Classification of mixtures according to the additivity approach, based on (6), (10) Ingredients, classified acc. to CLP as: Classification as mixture: Concentration (Total) kin-corrosive acc. to CLP Packing Group Skin-corrosive 1A 5 % 1 A I Skin-corrosive 1B 5 % 1 B II Skin-corrosive 1C 5 % 1 C III Skin-corrosive 1A and < 5 % Skin-corrosive (1A + 1B) Skin-corrosive (1A + 1B) and Skin-corrosive (1A + 1B + 1C) 5 % 1 B II < 5 % 5 % 1 C III Example A: A mixture containing 5% of a substance classified subcategory 1A and 50% of a substance classified subcategory 1B is classified subcategory 1A. Example B: A mixture containing 4% of a substance classified subcategory 1A and 1% of a substance classified sub-category 1B is classified subcategory 1B. Seite 4 von 8

5 The following exceptions must be noted: If specific concentration limits are defined for ingredients of mixtures, they have to be used for the purpose of classification. Specific concentration limits are listed in Annex VI of the CLP Regulation as well as in the C&L Inventory Database (see 3.2). Classification of these kinds of mixtures may also be necessary with concentrations of below 5%. Under certain circumstances, mixtures that contain acids and bases, inorganic salts, aldehydes, phenols and tensides can have a skin-corrosive effect in concentrations of below 1%, and these mixtures therefore need to be considered separately. In case of doubt, the precautionary principle should be applied and the higher Packing Group selected. In the case of mixtures that contain strong acids or bases, the ph value is used as a classification criterion. Under the legislation governing chemical substances, mixtures with a ph lower than or equal to 2 or higher than or equal to 11.5 are classified as skin-corrosive category 1 if no other data is available. If a mixture exhibits skincorrosive properties in a recognised in vitro test and if classification in one of the subgroups is not possible based on the data, the mixture is also classified as skincorrosive in category 1 (10). Additional information is to be used for the purpose of assignment to the appropriate Packing Group or exemption from the dangerous goods regulations (e.g. on applicability of the bridging principles or on the alkaline or acidity reserve). In case of doubt, the precautionary principle should be applied and the higher Packing Group selected. Mixtures with certain chemical properties cannot be classified on the basis of the additivity approach. This also includes mixtures with strongly acidic or strongly basic constituents. They are to be classified as skin-corrosive in subcategories 1A, 1B or 1C if they contain > 1% of a constituent that is classified in subcategory 1A, 1B or 1C and are to be assigned to the corresponding Packing Groups. The decision as to which mixtures this applies must be made on a case-to-case basis based on expert judgement. In case of doubt, decisions should be made in line with the precautionary principle and the higher Packing Group selected. 3.4 Special cases In the following cases, dangerous goods classification of substances and mixtures based on classifications according to the legislation on chemical substances is not possible or only possible with certain restrictions: If substances or ingredients of mixtures have not been classified to subcategories but are only listed as skin-corrosive Category 1 in Annex VI of the CLP Regulation (in these cases, the suitability of other methods for dangerous goods classification must be examined) If substances have not been classified as skin-corrosive based on the legislation on dangerous goods or if the safety data sheet does not contain any details on skin corrosion. This may be due to the following: Seite 5 von 8

6 1. The substance was tested for skin corrosion. The result was negative (i.e. the substance has no skin-corrosive effect); 2. No data is available on the substance in question, and it was therefore not possible to assess its properties (i.e.. it was not possible to make any statements on the skin-corrosive properties of the substance). In these cases, additional information has to be obtained to permit classification of these kinds of substances or mixtures with these kinds of ingredients. 4 Classification of mixtures for which no skin corrosion data are available based on the bridging principles If the mixture has not been tested for skin-corrosion but sufficient data is available on its individual ingredients as well as on similar tested mixtures, the following bridging principles may be applied. 4.1 Interpolation within a toxicity class For three mixtures with the same hazardous ingredients, where mixture A and mixture B belong to the same hazard category and mixture C has the same active hazardous ingredients in concentrations that are between those for the same hazardous substances in mixtures A and B, then mixture C is assumed to be in the same hazard category as A and B. Example: Table 3: Interpolation within a toxicity class, based on (6), (10). Mixtures A and B are classified as dangerous goods (class 8, PG II); the same classification is derived for mixture C. Mixture Constituents corrosive to the skin Dangerous good x y z Class Packing Group [%] [%] [%] A II B II C II 4.2 Classification of substantially similar mixtures There are two mixtures - A and B - each with two constituents: A = x + y B = x + z For mixture A classification is based on test data (e.g. skin-corrosive, class 8, PG II). Constituent x is present in mixture A and mixture B, and no data on skin corrosion is available for x. The concentration of constituent x is identical in both mixtures, however. The concentration of constituent y in mixture A corresponds to that of constituent z in mixture B. The hazard classification is known and identical for y and z (Class 8, same Packing Group). Mixture B is classified like mixture A. Seite 6 von 8

7 Example: Table 4: Bridging principles for substantially identical mixtures, based on (6), (10). Mixture A is classified as dangerous good (class 8, PG II); the same classification is derived for mixture B Mixture Ingredients Dangerous good Untested Corrosive to the skin x y z Class Packing Group [%] [%] [%] A II B II 4.3 Review of classification where the original concentration of skin-corrosive ingredients in a mixture has changed Reclassification is not necessary for the following changes in concentration: Table 5: Bridging principles following a change in the original concentration of skin-corrosive ingredients in a mixture (6), (10) Original concentration range of the ingredient Admissible change in original concentration of the ingredient 2.5 % ± 30 % 2.5 < C 10 % ± 20 % 10 < C 25 % ± 10 % 25 < C 100 % ± 5 % All changes in concentration exceeding the ranges specified in Table 4 result in reclassification of the mixture. 4.4 Review of classification following a change in the composition of a mixture Reclassification must be performed if the ingredients of a mixture have changed. 5 Literature (1) UN Recommendations on the Transport of Dangerous Goods - Model Regulations (2) OECD Guideline 404, Acute Dermal Irritation/Corrosion, (3) OECD Guideline 435, In Vitro Membrane Barrier Test Method for Skin Corrosion, (4) OECD Guideline 430, In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER), 2004 Seite 7 von 8

8 (5) OECD Guideline 431, In Vitro Skin Corrosion: Human Skin Model Test, (6) Verordnung (EG) Nr. 1272/2008 des Europäischen Parlaments und des Rates vom 16. Dezember 2008 über die Einstufung, Kennzeichnung und Verpackung von Stoffen und Gemischen, zur Änderung und Aufhebung der Richtlinien 67/548/EWG und 1999/45/EG und zur Änderung der Verordnung (EG) Nr. 1907/ (7) Globally Harmonized System of Classification and Labelling of Chemicals (GHS) (8) Richtlinie 67/548/EWG des Rates vom 27. Juni 1967 zur Angleichung der Rechts- und Verwaltungsvorschriften für die Einstufung, Verpackung und Kennzeichnung gefährlicher Stoffe (9) Richtlinie 1999/45/EG des Europäischen Parlaments und des Rates vom 31. Mai 1999 zur Angleichung der Rechts- und Verwaltungsvorschriften der Mitgliedstaaten für die Einstufung, Verpackung und Kennzeichnung gefährlicher Zubereitungen (10) ECHA, Guidance on the Application of the CLP Criteria Seite 8 von 8