PYRIDINE | Occupational Safety and Health Administration

PYRIDINE†

Chemical Identification
CAS #	110-86-1
Formula	C₅H₅N
Synonyms	azabenzene; azine

Physical Properties
Physical description	Colorless to yellow liquid with a nauseating, fish-like odor.
Boiling point	240°F	Molecular weight	79.1
Freezing point/melting point	-44°F	Vapor pressure	16 mmHg
Flash point	68°F	Vapor density	2.72
Specific gravity	0.983 at 68°F	Ionization potential	9.27 eV
Lower explosive limit (LEL)	1.8%	Upper explosive limit (UEL)	12.4%
NFPA health rating	3	NFPA fire rating	3
NFPA reactivity rating	0	NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs

Monitoring Methods Used by OSHA
Analyte code (IMIS no.)	2220
Sampling group
Sampler/Sampling media	2 XAD-7 tubes in series (100/50 mg) [SKC 226-95]
Sampling time^*	100 min
Sampling volume (TWA)^*	10 L
Sampling flow rate (TWA)^*	0.1 L/min
Sampling volume (STEL/Peak/C)^*
Sampling flow rate (STEL/Peak/C)^*
Analytical method instruments	GC-FID
Method reference	OSHA PV2295 (partially validated)
Notes
Special requirements

^* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Bulk/Wipe Method
Wipe Sampler/Sampling media
Bulk Method

On-Site Screening Techniques
Device
Model/Type
Sampling information (see manufacturer instructions)

**Exposure Limits**
OSHA PEL 8-hour TWA (ST) STEL (C) Ceiling Peak		NIOSH REL Up to 10-hour TWA (ST) STEL (C) Ceiling		ACGIH TLV© 8-hour TWA (ST) STEL (C) Ceiling		CAL/OSHA PEL 8-hour TWA (ST) STEL (C) Ceiling Peak
PEL-TWA	5 ppm (15 mg/m³)	REL-TWA	5 ppm (15 mg/m³)	TLV-TWA	1 ppm [1992]	PEL-TWA	5 ppm (15 mg/m³)
PEL-STEL		REL-STEL		TLV-STEL		PEL-STEL
PEL-C		REL-C		TLV-C		PEL-C
Skin notation	N	Skin notation	N	Skin notation	N	Skin notation	N
Notes: See 29 CFR 1910.1000 Table Z-1.		Notes:		Notes:		Notes:
Health factors: See NIH-NLM PubChem.		IDLH	1000 ppm
Carcinogenic classifications: IARC-3, TLV-A3		Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:

Additional Resources and Literature References

NOAA: CAMEO Chemicals - Pyridine

NIOSH: Pocket Guide to Chemical Hazards - Pyridine

Literature References

ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Pyridine. See annual publication for most recent information.
U.S. EPA Integrated Risk Information System: Pyridine (CASRN 110-86-1).
Damani, L.A., Crooks, P.A., Shaker, M.S., Caldwell, J., D'Souza, J. and Smith, R.L.: Species differences in the metabolic C- and N-oxidation, and N-methylation of [14C]pyridine in vivo. Xenobiotica 12(8): 527-534, 1982.
National Toxicology Program: NTP toxicology and carcinogenesis studies of pyridine (CAS No. 110-86-1) in F344/N rats, Wistar rats, and B6C3F1 mice (drinking water studies). Nat. Toxicol. Program Tech. Rep. Ser. 470: 1-330, 2000.
Nikula, K.J. and Lewis, J.L.: Olfactory mucosal lesions in F344 rats following inhalation exposure to pyridine at threshold limit value concentrations. Fundam. Appl. Toxicol. 23(4): 510-517, 1994.
[No authors listed]: Pyridine. IARC Monogr. Eval. Carcinog. Risks Hum. 77: 503-528, 2000.
Pohanish, R.P. (editor): Pyridine. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1988-1990.

Last Updated Date : 01/28/2021

PYRIDINE†

Chemical Identification

Physical Properties

Monitoring Methods Used by OSHA

Bulk/Wipe Method

On-Site Screening Techniques

Exposure Limits

Additional Resources and Literature References