Agent Name |
Pyridine |
CAS Number |
110-86-1 |
Formula |
C5-H5-N |
Major Category |
Nitrogen Compounds |
Synonyms |
Azabenzene; Azine; CP 32; Piridina [Italian]; Pirydyna [Polish]; Pyridin [German]; Pyridine; [ChemIDplus] UN1282 |
Category |
Pyridines |
Description |
Colorless to yellow liquid with a nauseating, fish-like odor; [NIOSH] |
Sources/Uses |
Used as a solvent for paint and rubber; used as an intermediate for pharmaceuticals, dyes, pesticides, textile finishes, and other chemicals; also used as a flavoring agent; [ACGIH] |
Comments |
Liquid causes first degree burns on short exposure. [CHRIS] In rat studies, pyridine produces anesthesia after inhalation of high concentrations and liver injury after sub-chronic feeding. The liver and kidneys are target organs in animal results. Workers avoid exposure because of its foul odor. Workers exposed to 125 ppm complained of transient nausea, headache, low back and abdominal discomfort, and urinary frequency without evidence of liver or kidney injury. [ACGIH] Pyridine and its derivatives are strong sensitizers. Allergic contact dermatitis reported in a laboratory technician; [Kanerva, p. 1190] An irritant and potential CNS depressant; May have effects on the liver and kidneys; [ICSC] |
Reference Link |
ATSDR - ToxFAQs - Pyridine |
Exposure Assessment |
Skin Designation (ACGIH) |
No |
TLV (ACGIH) |
1 ppm |
PEL (OSHA) |
5 ppm |
MAK |
5 ppm |
IDLH (NIOSH) |
1000 ppm |
Excerpts from Documentation for IDLHs |
Human data: Nausea, headache, insomnia, nervousness, and low back or abdominal discomfort with urinary frequency have occurred in individuals exposed to concentrations averaging 125 ppm for 4 hours/day for 1 to 2 weeks [Patty 1963]. Chronic poisoning with mild symptoms of central nervous system injury occurred in workers at a plant where pyridine vapor concentrations ranged from 6 to 12 ppm [Tessinger 1948]. |
Vapor Pressure |
20.8 mm Hg |
Odor Threshold Low |
0.23 ppm |
Odor Threshold High |
1.9 ppm |
Lethal Concentration |
LC50 (rats) = 28,500 mg/m3/1H |
Explanatory Notes |
Detection odor threshold from AIHA (mean = 0.66 ppm); Flash point = 20 deg C; |
Half Life |
Whole body: less than 24 hours; [TDR, p. 1062] |
Reference Link |
International Chemical Safety Cards (WHO/IPCS/ILO) |
Flammability (NFPA) |
3: may ignite at ambient temperature |
Adverse Effects |
Dermatotoxin |
Skin Burns |
Skin Sensitizer |
Yes |
Neurotoxin |
Other CNS Neurotoxin |
Hepatotoxin |
Hepatotoxin, Secondary |
Nephrotoxin |
Yes |
IARC Carcinogen |
Not Classifiable |
Links to Other NLM Databases |
Health Studies |
Human Health Effects from Hazardous Substances Data Bank: PYRIDINE
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