Class 8 Corrosive substances
The heading of Class 8 covers substances and articles containing substances of this class which by
chemical action attack epithelial tissue - of skin or mucous membranes - with which they are in
contact, or which in the event of leakage are capable of damaging or destroying other goods, or means
of transport. The heading of this class also covers other substances which form a corrosive liquid only
in the presence of water, or which produce corrosive vapour or mist in the presence of natural
moisture of the air.
Substances and articles of Class 8 are subdivided as follows:
C1-C11 Corrosive substances without subsidiary risk and articles containing such substances:
C1-C4 Acid substances:
C1 Inorganic, liquid;
C2 Inorganic, solid;
C3 Organic, liquid;
C4 Organic, solid;
C5-C8 Basic substances:
C5 Inorganic, liquid;
C6 Inorganic, solid;
C7 Organic, liquid;
C8 Organic, solid;
C9-C10 Other corrosive substances:
CF Corrosive substances, flammable:
CS Corrosive substances, self-heating:
CW Corrosive substances which, in contact with water, emit flammable gases:
CO Corrosive substances, oxidizing:
CT Corrosive substances, toxic and articles containing such substances:
CFT Corrosive substances, flammable, liquid, toxic;
COT Corrosive substances, oxidizing, toxic.
Classification and assignment of packing groups
Substances of Class 8 shall be classified in three packing groups according to the degree of danger
they present for carriage, as follows:
Packing group I: highly corrosive substances
Packing group II: corrosive substances
Packing group III: slightly corrosive substances.
Substances and articles classified in Class 8 are listed in Table A of Chapter 3.2. Allocation of
substances to packing groups I, II and III has been made on the basis of experience taking into account
such additional factors as inhalation risk (see 220.127.116.11.5) and reactivity with water (including the
formation of dangerous decomposition products).
A substance or preparation meeting the criteria of Class 8 having an inhalation toxicity of dusts and
mists (LC50) in the range 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.
Substances, including mixtures, not mentioned by name in Table A of Chapter 3.2 can be assigned to
the relevant entry of sub-section 18.104.22.168, and to the relevant packing group on the basis of the length
of time of contact necessary to produce full thickness destruction of human skin in accordance with
the criteria of (a) to (c) below.
Liquids, and solids which may become liquid during carriage, which are judged not to cause full
thickness destruction of human skin shall still be considered for their potential to cause corrosion to
certain metal surfaces. In assigning the packing group, account shall be taken of human experience in
instances of accidental exposure. In the absence of human experience, the grouping shall be based on
data obtained from experiments in accordance with OECD Test Guideline 4045 or 4356. A substance
which is determined not to be corrosive in accordance with OECD Test Guideline 4307 or 4318 may
be considered not to be corrosive to skin for the purposes of ADR without further testing.
(a) Packing group I is assigned to substances that cause full thickness destruction of intact skin
tissue within an observation period up to 60 minutes starting after the exposure time of 3
minutes or less;
(b) Packing group II is assigned to substances that cause full thickness destruction of intact skin
tissue within an observation period up to 14 days starting after the exposure time of more than
3 minutes but not more than 60 minutes;
(c) Packing group III is assigned to substances that:
- cause full thickness destruction of intact skin tissue within an observation period up
to 14 days starting after the exposure time of more than 60 minutes but not more
than 4 hours; or
- are judged not to cause full thickness destruction of intact skin tissue, but which exhibit
a corrosion rate on either steel or aluminium surfaces exceeding 6.25 mm a year at a test
temperature 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),
ISO 3574, Unified Numbering System
(UNS) G10200 or SAE 1020, and for testing aluminium, non-clad, types 7075-T6
or AZ5GU-T6 shall be used. An acceptable 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 substance being
tested is corrosive the follow up test on the other metal is not required.
5 OECD Guideline for the testing of chemicals No. 404 "Acute Dermal Irritation/Corrosion" 2002.
6 OECD Guideline for the testing of chemicals No. 435 "In Vitro Membrane Barrier Test Method for Skin Corrosion"
7 OECD Guideline for the testing of chemicals No. 430 "In Vitro Skin Corrosion: Transcutaneous Electrical
Resistance Test (TER)" 2004.
8 OECD Guideline for the testing of chemicals No. 431 "In Vitro Skin Corrosion: Human Skin Model Test" 2004.
Table 22.214.171.124.6: Table summarizing the criteria in 126.96.36.199.6
≤ 3 min
≤ 60 min
Full thickness destruction of intact skin
> 3 min ≤ 1 h
≤ 14 d
Full thickness destruction of intact skin
> 1 h ≤ 4 h
≤ 14 d
Full thickness destruction of intact skin
Corrosion rate on either steel or aluminium surfaces exceeding 6.25 mm a year at a test temperature of 55 ºC when tested on both materials
If substances of Class 8, as a result of admixtures, come into categories of risk different from those to
which the substances mentioned by name in Table A of Chapter 3.2 belong, these mixtures or
solutions shall be assigned to the entries to which they belong, on the basis of their actual degree of
NOTE: For the classification of solutions and mixtures (such as preparations and wastes), see also
On the basis of the criteria set out in paragraph 188.8.131.52.6, it may also be determined whether the nature
of a solution or mixture mentioned by name or containing a substance mentioned by name is such that
the solution or mixture is not subject to the provisions for this class.
Substances, solutions and mixtures, which are not classified as corrosive to skin or metal of category 1
according to Regulation (EC) No 1272/20083 may be considered as substances not belonging to
NOTE: UN No. 1910 calcium oxide and UN No. 2812 sodium aluminate, listed in the UN Model
Regulations, are not subject to the provisions of ADR.
Substances not accepted for carriage
Chemically unstable substances of Class 8 shall not be accepted for carriage unless the necessary
precautions have been taken to prevent the possibility of a dangerous decomposition or
polymerization under normal conditions of carriage. For the precautions necessary to prevent
polymerization, see special provision 386 of Chapter 3.3. To this end particular care shall be taken to
ensure that receptacles and tanks do not contain any substances liable to promote these reactions.
The following substances shall not be accepted for carriage:
- UN No. 1798 NITROHYDROCHLORIC ACID;
- chemically unstable mixtures of spent sulphuric acid;
- chemically unstable mixtures of nitrating acid or mixtures of residual sulphuric and nitric
acids, not denitrated;
- perchloric acid aqueous solution with more than 72% pure acid, by mass, or mixtures of
perchloric acid with any liquid other than water.
3 Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on
classification, labelling and packaging of substances and mixtures, amending and repealing Directive 67/548/EEC and
1999/45/EC; and amending Regulation (EC) No 1907/2006, published in the Official Journal of the European Union,
L 353, 31 December 2008, p 1-1355.
List of collective entries
Corrosive substances without subsidiary risk and articles containing such substances
Corrosive substances with subsidiary risk(s) and articles containing such substances
a Mixtures of solids which are not subject to the provisions of ADR and of corrosive liquids may be carried under
UN No. 3244 without being subject to the classification criteria of Class 8, provided there is no free liquid visible at the
time the substance is loaded or at the time the packaging, container or transport unit is closed. Each packaging shall
correspond to a design type which has passed the leakproofness test for Packing group II level.
b Chlorosilanes which, in contact with water or moist air, emit flammable gases, are substances of Class 4.3.
c Chloroformates having predominantly toxic properties are substances of Class 6.1.
d Corrosive substances which are highly toxic by inhalation, as defined in 184.108.40.206.4 to 220.127.116.11.9 are substances
of Class 6.1.
e UN No. 2505 AMMONIUM FLUORIDE, UN No. 1812 POTASSIUM FLUORIDE, SOLID, UN No. 1690
SODIUM FLUORIDE, SOLID, UN No. 2674 SODIUM FLUOROSILICATE, UN No. 2856 FLUOROSILICATES,
N.O.S., UN No. 3415 SODIUM FLUORIDE SOLUTION and UN No. 3422 POTASSIUM FLUORIDE SOLUTION are
substances of Class 6.1.