Safety data for hydrogen cyanide
The information on this web page is provided to help you to work safely, but it is intended to be an overview of hazards, not a replacement for a full Material Safety Data Sheet (MSDS). MSDS forms can be downloaded from the web sites of many chemical suppliers.
Toxicity data
Risk phrases
Safety phrases
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This information was last updated on September 3, 2003.
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for it. General
Synonyms: prussic acid, hydrocyanic acid, formonitrile
Molecular formula: HCN
CAS No: 74-90-8
EC No: 200-821-6
Physical data
Appearance: colourless or pale blue liquid, or colourless
gas, (depending upon temperature) with a bitter almond odour
Melting point: -14 C
Boiling point: 25.6 C
Vapour density:
Vapour pressure:
Specific gravity: 0.6899 at 18 C
Flash point: -18 C
Explosion limits:
Autoignition temperature:
Stability
Stable. Incompatible with acids, strong oxidizing agents. Highly flammable.
Toxicology
Very toxic by inhalation, ingestion and through skin contact.
Inhalation, ingestion or skin contact may be fatal. Note low LD50s below.
(The meaning of any abbreviations which appear in this section
is given
here.)
ORL-MUS LD50 3.7 mg kg-1
IHL-MUS LC50 323 ppm.
IV-MUS LD50 1 mg kg-1
IV-RBT LD50 <1 mg kg-1
ORL-MAN LDLO <1 mg kg-1
(The meaning of any risk phrases which appear in this section is
given here.)
R12 R26 R27 R28 R32.
Transport information
Personal protection
Safety glasses, gloves, good ventilation.
Only use if no suitable alternative chemical is available.
Do not work on your own. Keep a cyanide poisoning kit
available at all times, and ensure that fellow workers know how
to use it.
(The meaning of any safety phrases which appear in this section
is given here.)
S1 S2 S7 S9 S13 S16 S28 S29 S45.