Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available
Additional information:

No reliable data exists for skin sensitisation potential for HCN. However, skin sensitisation is not the endpoint of concern with HCN, a substance having high acute dermal and inhalatory toxicity. The amount of test material recommended for application in OECD Guideline test protocols would more likely result in toxicity or perhaps lethality than in sensitisation. As a precaution against dermal and respiratory exposure, this material has labeling instructions for handlers which advise against dermal and inhalation exposure by wearing personal protective equipment.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available
Additional information:

Hydrogen cyanide's high acute toxicity, with an LD50 of 68 mg/m3 for 6 hours in the rat, is the endpoint of concern for the inhalation route of exposure. For human exposure, the LD01 has been estimated to be 43 mg/m3 for a 4 hour exposure.

Justification for classification or non-classification

No classification is justified for the sensitisation potential of HCN, as no reliable data exists. Due to its high acute toxicity, it is classified as H300: Fatal if swallowed, H310: Fatal in contact with skin, H330: Fatal if inhaled. Package warnings are in place which advise use of protective clothing and gloves, and respiratory protection.