# NIOSH Pocket Guide to Chemical Hazards
Pyridine | CAS 110-86-1
C5H5N | RTECS UR8400000
Synonyms & Trade Names Azabenzene, Azine | DOT ID & Guide 1282 129
Exposure Limits | NIOSH REL: TWA 5 ppm (15 mg/m3)
OSHA PEL: TWA 5 ppm (15 mg/m3)
IDLH 1000 ppm | Conversion 1 ppm = 3.24 mg/m3
Physical Description Colorless to yellow liquid with a nauseating, fish-like odor.
MW: 79.1 | BP: 240°F | FRZ: -44°F | Sol: Miscible
VP: 16 mmHg | IP: 9.27 eV |  | Sp.Gr: 0.98
Fl.P: 68°F | UEL: 12.4% | LEL: 1.8% |
Class IB Flammable Liquid: Fl.P. below 73°F and BP at or above 100°F.
Incompatibilities & Reactivities Strong oxidizers, strong acids
Measurement Methods NIOSH 1613; OSHA 7
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet (flammable) Change: No recommendation Provide: Eyewash, Quick drench | First Aid (See procedures) Eye: Irrigate immediately Skin: Water flush immediately Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH/OSHA Up to 125 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode£/(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s)£ Up to 50 ppm: (APF = 50) Any chemical cartridge respirator with a full facepiece and organic vapor cartridge(s)/(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/(APF = 50) Any powered, air-purifying respirator with a tight-fitting facepiece and organic vapor cartridge(s)£/(APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece Up to 1000 ppm: (APF = 2000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode Emergency or planned entry into unknown concentrations or IDLH conditions: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus Escape: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin absorption, ingestion, skin and/or eye contact
Symptoms Irritation eyes; headache, anxiety, dizziness, insomnia; nausea, anorexia; dermatitis; liver, kidney damage
Target Organs Eyes, skin, central nervous system, liver, kidneys, gastrointestinal tract,
See also: INTRODUCTION