Ammonia, anhydrous

Endpoint summary

Description of key information

No modern reliable studies (e.g. GLP/OECD test guidelines studies) are available on the skin and eye irritation effects of the anhydrous ammonia. Waivers are proposed for skin and eye irritation in accordance with Column 2 of Annexes VII, No. 8.1 and 8.2 respectively on the basis that anhydrous ammonia and its aqueous salts are classified as corrosive. Additional testing is not required and is considered to be unjustified both scientifically and on animal welfare grounds. Data from supporting studies confirms that gaseous and aqueous forms of ammonia are corrosive/irritating to the skin.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Supporting studies are available on the skin and eye irritation effects of the substance.

 

In a first study, rats were exposed for 5-60 minutes at various concentrations, however no details were given (Prokop'eva et al.,1973). The visible signs of skin pathology appeared only at an ammonia concentration of 20-30 mg/L and higher, mainly in the form of a burn around the anus and in the region of the external genitalia. The LC50 was 112 mg/L after 15 mins of exposure.

 

In a second study, different concentrations of aqueous ammonia were investigated in New Zealand White rabbits (Vernot et al., 1977). The authors reported that 12% aqueous ammonia was corrosive to the skin of rabbits following a 4 hour occlusive exposure on shaved skin, whereas 10% aqueous ammonia was not corrosive to the skin of rabbits.

 

According to Part 3 of Annex VI of the CLP Regulation 1272/2008/EC, anhydrous ammonia and its aqueous solutions, have a harmonised classification for corrosive effects. Gaseous and aqueous forms of ammonia are classified for corrosivity as: Category 1B, H314 “Causes severe skin burns and eye damage” according to Annex VI of the CLP Regulation 1272/2008/EC. Waivers are proposed for skin and eye irritation in accordance with Column 2 of Annexes VII, No. 8.1 and 8.2 respectively on the basis that the substance is classified as corrosive. The specific rules for adaptation from Column 1 of the standard information requirements in Column 2 state that testing for skin irritation/corrosion and eye irritation is not required for substances which are classified as corrosive to the skin. Additional testing for skin irritation eye irritation is not required and is considered to be unjustified both scientifically and on animal welfare grounds.

 

Available non-standard data have been reported as supporting information.

 

Respiratory irritation

Animal data and human reports indicate that the substance is a respiratory irritant.

 

Justification for selection of skin irritation / corrosion endpoint:

Anhydrous ammonia and its aqueous solutions are corrosive to the skin and have a harmonised classification for these effects. A waiver is proposed for skin irritation/corrosion effects in accordance with Annex VII, No. 8.1 Column 2 of the REACH Regulation on the basis that the substance is classified as corrosive. Additional testing for skin irritation/corrosion is not required and is considered to be unjustified both scientifically and on animal welfare grounds. Data from an older study using different concentrations of aqueous solution of ammonia conducted using a similar method to OECD 404 (Vernot et al., 1977) indicated that solutions of 12 % were corrosive to rabbits.

 

Justification for selection of eye irritation endpoint:

Anhydrous ammonia and its aqueous solutions are corrosive to the eyes and have a harmonised classification for these effects. A waiver is proposed for eye irritation effects in accordance with Annex VII, No. 8.2 Column 2 of the REACH Regulation on the basis that the substance is classified as corrosive. Additional testing for eye irritation/corrosion is not required and is considered to be unjustified both scientifically and on animal welfare grounds.

 

Effects on skin irritation/corrosion: corrosive

 

Effects on eye irritation: irriversible damage

 

Effects on respiratory irritation: irritating

Justification for classification or non-classification

Anhydrous ammonia and its aqueous solutions have a harmonised classification for corrosive effects. The gaseous and aqueous forms of ammonia are classified as: Category 1B, H314 “Causes severe skin burns and eye damage” according to Annex VI of the CLP Regulation 1272/2008/EC. No change to the harmonised classification is proposed. Regarding corrosive effects, specific concentration limits have proposed for aqueous solutions of ammonia. Aqueous solutions ≥ 5% are classified as: Skin corrosion category 1B; H314: Causes severe burns and eye damage. According to Table 3.1 of CLP, ammonia is classified H335 - May cause respiratory irritation (C≥5% STOT SE 3).