PARAQUAT (PARAQUAT DICHLORIDE) | Occupational Safety and Health Administration

PARAQUAT (PARAQUAT DICHLORIDE)†

Chemical Identification
CAS #	4685-14-7
Formula	C₁₂H₁₄N₂+2
Synonyms	1,1'-dimethyl-4,4'-bipyridinium dichloride; N,N'-dimethyl-4,4'-bipyridinium dichloride; paraquat chloride; paraquat dichloride

Physical Properties
Physical description	[herbicide] [Note: Paraquat may also be found commercially as a methyl sulfate
Boiling point	decomposes	Molecular weight	257.18
Freezing point/melting point	572°F (decomposes)	Vapor pressure	<0.0000001 mmHg
Flash point		Vapor density
Specific gravity	1.24	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.)	1982 (respirable dust)
Sampling group
Sampler/Sampling media	PTFE filter, 1 µm [SKC 225-2705]
Sampling time^*
Sampling volume (TWA)^*	40-1000 L
Sampling flow rate (TWA)^*	1-4 L/min
Sampling volume (STEL/Peak/C)^*
Sampling flow rate (STEL/Peak/C)^*
Analytical method instruments	HPLC-UV
Method reference	NIOSH 5003 (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
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	0.5 mg/m³ (resp dust)	REL-TWA	0.1 mg/m³ (resp)	TLV-TWA	0.05 mg/m³ (inhalable particulate matter) [2017]	PEL-TWA	0.5 mg/m³ (total particulates), 0.1 mg/m³ (respirable sizes)
PEL-STEL		REL-STEL		TLV-STEL		PEL-STEL
PEL-C		REL-C		TLV-C		PEL-C
Skin notation	Y	Skin notation	Y	Skin notation	Y	Skin notation	Y
Notes: See 29 CFR 1910.1000 Table Z-1.		Notes:		Notes:		Notes: See footnote [n]
Health factors: See NIH-NLM PubChem.		IDLH	1 mg/m³
Carcinogenic classifications: TLV-A4		Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:

Additional Resources and Literature References

NOAA: CAMEO Chemicals - Paraquat dichloride

NIOSH: Pocket Guide to Chemical Hazards - Paraquat (Paraquat dichloride)

Literature References

ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Paraquat [4685-14-7] as the cation. See annual publication for most recent information.
Hertzman, C., Wiens, M., Bowering, D., Snow, B. and Caine D.: Parkinson's disease: a case-control study of occupational and environmental risk factors. Am. J. Ind. Med. 17(3): 349-355, 1990.
McCormack, A.L., et al.: Environmental risk factors and Parkinson's disease: selective degeneration of nigral dopaminergic neurons caused by the herbicide paraquat. Neurobiol. Dis. 10(2): 119-127, 2002.
Pohanish, R.P. (editor): Paraquat. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1784-1787.
Ranjbar, A., Pasalar, P., Sedighi, A. and Abdollahi, M.: Induction of oxidative stress in paraquat formulating workers. Toxicol. Lett. 131(3): 191-194, 2002.
Suntres, Z.E.: Role of antioxidants in paraquat toxicity. Toxicology 180(1): 65-77, 2002.

Last Updated Date : 01/07/2021

PARAQUAT (PARAQUAT DICHLORIDE)†

Chemical Identification

Physical Properties

Monitoring Methods Used by OSHA

Bulk/Wipe Method

On-Site Screening Techniques

Exposure Limits

Additional Resources and Literature References