General classification provisions
Substances and articles of Class8 are subdividedas follows:
C1-C11 Corrosive substances without subsidiary risk and articles containing such substances:
C1-C4 Acid substances:
C1Inorganic, liquid;
C2Inorganic, solid;
C3Organic, liquid;
C4Organic, solid;
C5-C8 Basic substances:
C5Inorganic, liquid;
C6Inorganic, solid;
C7Organic, liquid;
C8Organic, solid;
C9-C10Other corrosive substances:
C9Liquid;
C10Solid;
C11Articles;
CFCorrosive substances, flammable:
CF1Liquid;
CF2Solid;
CSCorrosive substances, self-heating:
CS1Liquid;
CS2Solid;
CWCorrosive substances which, in contact with water, emit flammable gases:
CW1Liquid;
CW2Solid;
COCorrosive substances, oxidizing:
CO1Liquid;
CO2Solid;
CTCorrosive substances, toxic and articles containing such substances:
CT1Liquid;
CT2Solid;
CT3Articles;
CFTCorrosive substances, flammable, liquid, toxic;
COTCorrosive substances, oxidizing, toxic.
Substances and mixtures of Class 8 are divided among the three packing groups according to their degree of danger in carriage:
(a)Packing group I: very dangerous substances and mixtures;
(b)Packing group II:substances and mixtures presenting medium danger;
(c)Packing group III:substances and mixtures that present minor danger.
Allocation of substances listed in Table A of Chapter 3.2 to the packing groups in Class 8 has been made on the basis of experience taking into account such additional factors as inhalation risk (see 2.2.8.1.4.5) and reactivity with water (including the formation of dangerous decomposition products).
New substances and mixtures can be assigned to packing groups on the basis of the length of time of contact necessary to produce irreversible damage of intact skin tissue in accordance with the criteria in 2.2.8.1.5. Alternatively, for mixtures, the criteria in 2.2.8.1.6 can be used.
A substance or mixture meeting the criteria of Class 8 having an inhalation toxicity of dusts and mists (LC50) in therange of packing group I, but toxicity through oral ingestion or dermal contact only in the range of packing group III or less, shall be allocated to Class 8 (see 2.2.61.1.7.2).
Packing group assignment for substances and mixtures
Existing human and animal data including information from single or repeated exposure shall be the first line of evaluation, as they give information directly relevant to effects on the skin.
In assigning the packing group in accordance with 2.2.8.1.4.4, account shall be taken of human experience in instances of accidental exposure. In the absence of human experience the assignment shall be based on data obtained from experiments in accordance with OECD Test Guideline 4045or 4356.Asubstance or mixture which is determined not to be corrosive in accordance with OECD Test Guideline 4307or 4318may be considered not to be corrosive to skin for the purposes of ADR without further testing.
Packing groups are assigned to corrosive substances in accordance with the following criteria (see table 2.2.8.1.5.3):
(a)Packing groupI is assigned to substances that cause irreversible damage of intact skin tissuewithin an observation period up to 60 minutes starting after the exposure time of threeminutes or less;
(b)Packing group II is assigned to substances that cause irreversible damage of intact skin tissuewithin an observation period up to 14 days starting after the exposure time of more than threeminutes but not more than 60 minutes;
(c)Packing group III is assigned to substances that:
(i)Cause irreversible damage of intact skin tissue within an observation period up to 14days starting after the exposure time of more than 60 minutes but not more than 4hours; or
5 OECD Guideline for the testing of chemicals No. 404 "Acute Dermal Irritation/Corrosion" 2015
6 OECD Guideline for the testing of chemicals No. 435 "In Vitro Membrane Barrier Test Method for Skin Corrosion” 2015
7 OECD Guideline for the testing of chemicals No. 430 "In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER)” 2015
8 OECD Guideline for the testing of chemicals No. 431 "In Vitro Skin Corrosion: Human Skin Model Test" 2015
(ii)Are judged not to cause irreversible damage of intact skin tissue but which exhibit acorrosion rate on either steel or aluminium surfaces exceeding 6.25 mm a year at a testtemperature of 55 °C when tested on both materials. For the purposes of testing steel,type S235JR+CR (1.0037 resp. St 37-2), S275J2G3+CR (1.0144 resp. St 44-3), ISO3574 or Unified Numbering System (UNS) G10200 or a similar type or SAE 1020,and for testing aluminium, non-clad, types 7075–T6 or AZ5GU-T6 shall be used. Anacceptable test is prescribed in the Manual of Tests and Criteria, Part III, Section 37.
NOTE:Where an initial test on either steel or aluminium indicates the substancebeing tested is corrosive the follow up test on the other metal is not required.
Tablo 2.2.8.1.5.3: Table summarizing the criteria in 2.2.8.1.5.3
|
Packing Group |
Exposure Time |
Observation Period |
Effect |
|
I |
≤ 3 min |
≤ 60 min |
Irreversible damage of intact skin |
|
II |
> 3 min ≤ 1 h |
≤ 14 d |
Irreversible damage of intact skin |
|
III |
> 1 h ≤ 4 h |
≤ 14 d |
Irreversible damage of intact skin |
|
III |
– |
– |
Corrosion rate on either steel or aluminium surfacesexceeding 6.25 mm a year at a test temperature of 55ºC when tested on both materials |
Alternative packing group assignment methods for mixtures: Step-wise approach
General provisions
For mixtures it is necessary to obtain or derive information that allows the criteria to be applied to the mixture for the purpose of classification and assignment of packing groups. The approach to classification and assignment of packing groups is tiered, and is dependent upon the amount of information available for the mixture itself, for similar mixtures and/or for its ingredients. The flow chart of Figure 2.2.8.1.6.1 below outlines the process to be followed:
Figure 2.2.8.1.6.1: Step-wise approach to classify and assign packing group of corrosive mixtures
Bridging principles
Where a mixture has not been tested to determine its skin corrosion potential, but there are sufficient data on both the individual ingredients and similar tested mixtures to adequately classify and assign a packing group for the mixture, these data will be used in accordance with the following bridging principles. This ensures that the classification process uses the available data tothe greatest extent possible in characterizing the hazards of the mixture.
(a)Dilution: If a tested mixture is diluted with a diluent which does not meet the criteria for Class8 and does not affect the packing group of other ingredients, then the new diluted mixturemay be assigned to the same packing group as the original tested mixture.
NOTE:In certain cases, diluting a mixture or substance may lead to anincrease in the corrosive properties. If this is the case, this bridging principlecannot be used.
(b)Batching: The skin corrosion potential of a tested production batch of a mixture can beassumed to be substantially equivalent to that of another untested production batch of thesame commercial product when produced by or under the control of the same manufacturer,unless there is reason to believe there is significant variation such that the skin corrosionpotential of the untested batch has changed. If the latter occurs, a new classification isnecessary.
(c)Concentration of mixtures of packing group I: If a tested mixture meeting the criteria forinclusion in packing group I is concentrated, the more concentrated untested mixture may beassigned to packing group I without additional testing.
(d)Interpolation within one packing group: For three mixtures (A, B and C) with identicalingredients, where mixtures A and B have been tested and are in the same skin corrosionpacking group, and where untested mixture C has the same Class 8 ingredients as mixturesA and B but has concentrations of Class 8 ingredients intermediate to the concentrations inmixtures A and B, then mixture C is assumed to be in the same skin corrosion packing groupas A and B.
(e)Substantially similar mixtures: Given the following:
(i)Two mixtures: (A+B) and (C+B);
(ii)The concentration of ingredient B is the same in both mixtures;
(iii)The concentration of ingredient A in mixture (A+B) equals the concentration ofingredient C in mixture (C+B);
(iv)Data on skin corrosion for ingredients A and C are available and substantiallyequivalent, i.e. they are the same skin corrosion packing group and do not affect theskin corrosion potential of B.
If mixture (A+B) or (C+B) is already classified based on test data, then the other mixture may be assigned to the same packing group.
Calculation method based on the classification of the substances
Where a mixture has not been tested to determine its skin corrosion potential, nor is sufficient data available on similar mixtures, the corrosive properties of the substances in the mixture shall be considered to classify and assign a packing group.
Applying the calculation method is only allowed if there are no synergistic effects that make the mixture more corrosive than the sum of its substances. This restriction applies only if packing group II or III would be assigned to the mixture.