CHLORPYRIFOS

Chemical Identification
CAS #	2921-88-2
Formula	C₉H₁₁Cl₃NO₃PS
Synonyms	chlorpyrifos-ethyl; O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate; Dursban; phosphorothioate; phosphorothioic acid

Physical Properties
Physical description	Colorless to white, crystalline solid with a mild, mercaptan-like odor.
Boiling point	320°F (decomposes)	Molecular weight	350.6
Freezing point/melting point	108°F	Vapor pressure	0.00002 mmHg
Flash point		Vapor density	12.09
Specific gravity	1.40 (liquid at 110°F)	Ionization potential
Lower explosive limit (LEL)		Upper explosive limit (UEL)
NFPA health rating		NFPA fire rating
NFPA reactivity rating		NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs

Monitoring Methods Used by OSHA
Analyte code (IMIS no.)	0681
Sampling group
Sampler/Sampling media	OSHA versatile sampler (OVS-2) - 13 mm XAD-2 tube (270/140 mg) with GFF enclosed [SKC 226-30-16]
Sampling time^*	480 min
Sampling volume (TWA)^*	480 L
Sampling flow rate (TWA)^*	1 L/min
Sampling volume (STEL/Peak/C)^*	15 L
Sampling flow rate (STEL/Peak/C)^*	1 L/min
Analytical method instruments	GC-FPD
Method reference	OSHA 62 (fully 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	Wipe with GFF (37 mm), Type A/E [AP4003705]
Bulk Method	Limit the amount of bulk submitted to 1 g or 1 mL.

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		REL-TWA	0.2 mg/m³	TLV-TWA	0.1 mg/m³ (inhalable fraction and vapor) [2000]	PEL-TWA	0.2 mg/m³
PEL-STEL		REL-STEL		TLV-STEL		PEL-STEL
PEL-C		REL-C		TLV-C		PEL-C
Skin notation	NA	Skin notation	Y	Skin notation	Y	Skin notation	Y
Notes: Not established		Notes:		Notes: BEI®		Notes:
Health factors: See NIH-NLM PubChem.		IDLH
Carcinogenic classifications: TLV-A4		Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:

Additional Resources and Literature References

NOAA: CAMEO Chemicals - Chlorpyrifos

NIOSH: Pocket Guide to Chemical Hazards - Chlorpyrifos

Literature References

ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Chlorpyrifos. See annual publication for most recent information.
US Environmental Protection Agency Integrated Risk Information System: Chlorpyrifos (CASRN 2921-88-2).
Albers, J.W., Garabrant, D.H., Schweitzer, S.J., Garrison, R.P., Richardson, R.J. and Berent, S.: The effects of occupational exposure to chlorpyrifos on the peripheral nervous system: a prospective cohort study. Occup. Environ. Med. 61(3): 201-211, 2004.
Kaplan, J.G., Kessler, J., Rosenberg, N., Pack, D. and Schaumburg, H.H.: Sensory neuropathy associated with Dursban (chlorpyrifos) exposure. Neurology 43(11): 2193-2196, 1993.
Meggs, W.J.: Permanent paralysis at sites of dermal exposure to chlorpyrifos. J. Toxicol. Clin. Toxicol. 41(6): 883-886, 2003.
Miranda, J., et al.: Onset of grip- and pinch-strength impairment after acute poisonings with organophosphate insecticides. Int. J. Occup. Environ. Health 8(1): 19-26, 2002.
Pohanish, R.P. (editor): Chlorpyrifos. Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 602-604.
Sams, C., Cocker, J. and Lennard, M.S.: Biotransformation of chlorpyrifos and diazinon by human liver microsomes and recombinant human cytochrome P450s (CYP). Xenobiotica 34(10): 861-873, 2004.

Last Updated Date : 12/21/2020

CHLORPYRIFOS

Chemical Identification

Physical Properties

Monitoring Methods Used by OSHA

Bulk/Wipe Method

On-Site Screening Techniques

Exposure Limits

Additional Resources and Literature References