O-DICHLOROBENZENE | Occupational Safety and Health Administration

O-DICHLOROBENZENE†

Chemical Identification
CAS #	95-50-1
Formula	C₆H₄Cl₂
Synonyms	o-DCB; 1,2-dichlorobenzene; ortho-dichlorobenzene; o-dichlorobenzol

Physical Properties
Physical description	Colorless to pale-yellow liquid with a pleasant, aromatic odor.
Boiling point	357°F	Molecular weight	147
Freezing point/melting point	1°F	Vapor pressure	1 mmHg@68°F, 1.5 mmHg@77°F
Flash point	151°F	Vapor density	5.05
Specific gravity	1.306	Ionization potential	9.06 eV
Lower explosive limit (LEL)	2.2%	Upper explosive limit (UEL)	9.2%
NFPA health rating	2	NFPA fire rating	2
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.)	0867
Sampling group
Sampler/Sampling media	CSC tube (100/50 mg) [SKC 226-01]
Sampling time^*
Sampling volume (TWA)^*	1-10 L
Sampling flow rate (TWA)^*	0.01-0.2 L/min
Sampling volume (STEL/Peak/C)^*
Sampling flow rate (STEL/Peak/C)^*
Analytical method instruments	GC-FID
Method reference	NIOSH 1003 (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		REL-TWA		TLV-TWA	25 ppm [1990]	PEL-TWA	25 ppm (150 mg/m³)
PEL-STEL		REL-STEL		TLV-STEL	50 ppm [1990]	PEL-STEL
PEL-C	50 ppm (300 mg/m³)	REL-C	50 ppm (300 mg/m³)	TLV-C		PEL-C	50 ppm
Skin notation	N	Skin notation	N	Skin notation	N	Skin notation	Y
Notes: See 29 CFR 1910.1000 Table Z-1.		Notes:		Notes:		Notes:
Health factors: See NIH-NLM PubChem.		IDLH	200 ppm
Carcinogenic classifications: IARC-3, TLV-A4, EPA-D		Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:

Additional Resources and Literature References

NOAA: CAMEO Chemicals - O-Dichlorobenzene

NIOSH: Pocket Guide to Chemical Hazards - o-Dichlorobenzene

Literature References

ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - o-Dichlorobenzene. See annual publication for most recent information.
U.S. EPA Integrated Risk Information System: 1,2-Dichlorobenzene (CASRN 95-50-1).
Hissink, A.M., Van Ommen, B., Krüse, J. and Van Bladeren, P.J.: A physiologically based pharmacokinetic (PB-PK) model for 1,2-dichlorobenzene linked to two possible parameters of toxicity. Toxicol. Appl. Pharmacol. 145(2): 301-310, 1997.
Kumagai, S. and Matsunaga, I.: Relations between exposure to o-dichlorobenzene and concentrations of urinary metabolites. J. Occup. Health 39(2): 124-129, 1997.
McDougal, J.N., Grabau, J.H., Dong, I., Mattie, D.R. and Jepson, G.W.: Inflammatory damage to skin by prolonged contact with 1,2-dichlorobenzene and chloropentafluorobenzene. Microsc. Res. Tech. 37(3): 214-220, 1997.
Pohanish, R.P. (editor): Dichlorobenzenes. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 799-804.
Violante, F.S., Milani, S., Malenchini, G. and Barbieri, A.: Chloracne due to o-dichlorobenzene in a laboratory worker. Contact Dermatitis 52(2): 108, 2005.
Zapata-Gayon, C., Zapata-Gayon, N. and Gonzalez-Angulo, A.: Clastogenic chromosomal aberrations in 26 individuals accidentally exposed to ortho dichlorobenzene vapors in the National Medical Center in Mexico City. Arch. Environ. Health 37(4): 231-235, 1982.
Zenser, L.-P., Lang, A. and Knecht, U.: N-Acetyl-S-(dichlorophenyl)cysteines as suitable biomarkers for the monitoring of occupational exposure to 1,2-dichlorobenzene. Int. Arch. Occup. Environ. Health 69(4): 252-254, 1997.

Last Updated Date : 01/07/2021

O-DICHLOROBENZENE†

Chemical Identification

Physical Properties

Monitoring Methods Used by OSHA

Bulk/Wipe Method

On-Site Screening Techniques

Exposure Limits

Additional Resources and Literature References