Arsenic acid

Endpoint summary

Description of key information

Arsenic acid was found to be corrosive to the skin. 
Arsenic induced irritant effects on eyes.

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)

Additional information

In a primary dermal irritation study performed similarly to OECD guideline 404 and in compliance with GLP, six (3/sex) New-Zealand White rabbits were dermally exposed to 0.5 mL of undiluted Desiccant L-10 (arsenic acid), under a semi-occlusive bandage for 4 hours to clipped skin of the dorsal surface (scapular to lumbar region). Animals were then observed for 24 hours. Irritation was scored by the method of Draize (1959).

 

Three of the six animals exhibited tissue destruction (necrosis) at the application site at 4.5 hours post-exposure (30 min. after removal of wrappings); the other three animals exhibited moderate to severe erythema and edema. All six animals were found dead within 24 hours after dosing. In this study, arsenic acid was found to be corrosive when applied topically to the rabbit. 

 

In an eye irritation study conducted similarly to the OECD Guideline 405 and in compliance with GLP, 9 (8 males, 1 female) rabbits of the New Zealand White strain were exposed to 0.1 mL of undiluted Desiccant L-10 (arsenic acid) in their right eye while the other eye corresponded to the control. Treated and control eyes of six animals remained unwashed. Twenty seconds after instillation, both eyes of the remaining three animals were rinsed for one minute with lukewarm tap water. The eyes were observed at 1, 24, 48 and 72 hours and 7, 10, 14, 17 and 21 days after instillation and graded according to the method of Draize (1959).

 

All nine animals exhibited moderate to severe conjunctival irritation (redness, chemosis, discharge), conjunctival necrosis, iridial damage and extensive corneal opacity and/or ulceration. Effects were slightly less severe in the washed eyes. 1/3 animal with washed eyes was free of ocular irritation within 14 days post-instillation. Remaining animals continued to exhibit severe irritation (including corneal opacities) at termination of the study (Day 21). All animals with non-washed eyes had severe irritation prior to being found dead or prior to sacrifice for humane reasons on Day 9. Mean individual scores at 24, 48 and 72 h after exposure for animals with unwashed eyes were 3, 3, 4, 4, 3 for cornea score; 1.3, 1, 1.7, 2, 1 for iris score; 1, 1.3, 2.3, 1.3, 1.7 for conjunctivae score and 2, 2, 2.3, 3, 2 for chemosis score. Mean individual scores at 24, 48 and 72 h after exposure for animals with washed eyes were 3, 1.3, 1 for cornea score; 1.3, 1, 1 for iris score; 2, 2.7, 2.7 for conjunctivae score and 3, 2.3, 2.7 for chemosis score.

Effects on skin irritation/corrosion: corrosive

Effects on eye irritation: irritating

Justification for classification or non-classification

According to skin irritation test results, arsenic acid should be classified as:

- corrosive to the skin, ‘R34 Causes burns’ according to the criteria of Annex VI of the Directive 67/548/EEC, and

- ‘ Category 1: Corrosive 1C’ in CLP Regulation (EC) No. 1272/2008.

According to eye irritation test results, arsenic acid should be classified as: - ‘R41 Risk of serious damage to eyes’ according to the criteria of Annex VI of the Directive 67/548/EEC, and - ‘Irreversible effects on the eye (Category 1)’ in CLP Regulation (EC) No. 1272/2008.