Major Category
Nitrogen Compounds
Synonyms
Azabenzene; Azine; CP 32; Piridina [Italian]; Pirydyna [Polish]; Pyridin [German]; Pyridine; [ChemIDplus] UN1282
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] Allergic contact dermatitis reported in a laboratory technician; [Kanerva, p. 1831] An irritant and potential CNS depressant; May have effects on the liver and kidneys; [ICSC]
Skin Designation (ACGIH)
Insufficient data
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 (rat) = 28,500 mg/m3/1H
Explanatory Notes
Detection odor threshold from AIHA (mean = 0.66 ppm); Flash point = 20 deg C; VP from HSDB;
Half Life
Whole body: less than 24 hours; [TDR, p. 1062]
NFPA
may ignite at ambient temp
Neurotoxin
Other CNS neurotoxin
Hepatotoxin
Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion
IARC Carcinogen
Possible (2b)
ACGIH Carcinogen
Confirmed Animal
Diseases
Occupational diseases associated with exposure to this agent:
Processes
Industrial Processes with risk of exposure:
Activities
Activities with risk of exposure: