Registration Dossier

Administrative data

Description of key information

Irritation and corrosion studies are not relevant for HCN, due to the extremely high acute toxicity of the substance.  HCN is absorbed via the skin, eye, lung and gastrointestinal tract.  Acute toxicity and possibly lethality occur before irritation develops.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
no study available

Eye irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Testing for skin and eye irritation is not scientifically indicated, due to the high acute toxicity of HCN. The amount of test material required in a standard skin and eye irritation study (500 and 100 mg/animal, respectively) is considerably above the level of systemic toxicity of cyanide. For example, for HCN, the dermal LD50 in rabbits is 2.34 mg/kg bw in abraded skin, and the ocular toxicity is 1.04 mg/kg bw. Recommended precautions for handling of HCN include respiratory protection to prevent lung inhalation, and barrier protection for eye and skin.

Justification for classification or non-classification

Classification as a skin or eye irritant is not appropriate as no reliable data exists. The extremely high acute toxicity of HCN indicates that it is classified as an acute toxicant, with appropriate warnings to avoid skin and eye contact. In this way, irritation effects will be precluded.