Chemical
Potassium cyanide
CAS 151-50-8 · EC 205-792-3 · CKN
- Signal word
- Danger
- CAS
- 151-50-8
- EC number
- 205-792-3
- UK/EU status
- 1 rule
Handle chemistry safely
Wear gloves and eye protection, work with good ventilation, and read the supplier’s safety data sheet before use. Hazard information here is a summary, not a replacement for it. Dispose of all photographic chemistry correctly, in line with local laws and your local authority’s guidance. Never mix waste solutions, and check the supplier’s safety data sheet before disposing of anything.
Hazards
Official EU classification (CLP Annex VI).
Harmonised classes: Acute Tox. 2 (Inhalation)* (H330); Acute Tox. 1 (Dermal) (H310); Acute Tox. 2 (Oral)* (H300); Aquatic Acute 1 (H400); Aquatic Chronic 1 (H410). Harmonised labelling also carries EUH032 (contact with acids liberates very toxic gas).
Signal word: Danger
Acute toxicity · Hazardous to the environment
| Code | Hazard statement |
|---|---|
| H330 | Fatal if inhaled. |
| H310 | Fatal in contact with skin. |
| H300 | Fatal if swallowed. |
| H400 | Very toxic to aquatic life. |
| H410 | Very toxic to aquatic life with long lasting effects. |
| EUH032 | Contact with acids liberates very toxic gas. |
UK and EU rules
- UK Poisons Act 1972: REGULATED poison (metal cyanides) – EPP licence required for members of the public (GOV.UK list of chemicals, checked 10 October 2026)
Photographic uses
- historical wet plate fixer (not recommended)