BENZENE | Occupational Safety and Health Administration

BENZENE‡

Chemical Identification
CAS #	71-43-2
Formula	C₆H₆
Synonyms	benzine; benzol; cyclohexatriene; phenyl hydride

Physical Properties
Physical description	Highly flammable colorless to light-yellow liquid with a petroleum-like odor.
Boiling point	176.2°F	Molecular weight	78.11
Freezing point/melting point	41.9°F	Vapor pressure	75 mmHg
Flash point	12°F	Vapor density	2.77
Specific gravity	0.88	Ionization potential	9.24 eV
Lower explosive limit (LEL)	1.2%	Upper explosive limit (UEL)	8%
NFPA health rating	2	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.)	0320	0320
Sampling group	OVSG-1
Sampler/Sampling media	CSC tube (100/50 mg) [SKC 226-01]	SKC 575-002 Passive Sampler [SKC 575-002]
Sampling time^*	240 min (15 min STEL)	240 min TWA; 10 min Peak; 15 min STEL (Note: SKC 575-002 Passive Samplers must be exposed for at least 10 min)
Sampling volume (TWA)^*	12 L
Sampling flow rate (TWA)^*	0.05 L/min
Sampling volume (STEL/Peak/C)^*	0.75 L
Sampling flow rate (STEL/Peak/C)^*	0.05 L/min
Analytical method instruments	GC-FID	GC-FID
Method reference	OSHA 5000 (fully validated)	OSHA 1005 v.2.1 (fully validated)
Notes		To obtain sampling and analytical error similar to that available with active sampling, knowledge of the atmospheric pressure and temperature are required, and these should be obtained using NIST-traceable devices. If that is not possible, temperature is assumed to be 22.2 °C, and the atmospheric pressure is estimated based on the elevation of the sampling location. When estimates are used in place of traceable measurements the sampling and analytical error associated with passive sampling is substantially increased, and this makes it more difficult to demonstrate over exposures after considering the 95% lower confidence limit.
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	Detector tube	Detector tube	Detector tube	CMS Chip	CMS Chip
Model/Type	Gastec 121	Matheson-Kitagawa 8014-118SC	Dräger - Benzene 5/b 6728071	Benzene, 0.05-2.5 ppm range; Benzene, 0.2-10 ppm range	Benzene, 0.5-10 ppm range; Benzene, 10-250 ppm range
Sampling information (see manufacturer instructions)	1-4 strokes, 0.5-120 ppm range, uncertainty 16.4% for 50-20 ppm, 8.2% for 20-60 ppm	Follow mfr instructions, 0.2-100 ppm range	20 strokes, 1-50 ppm range, 25% uncertainty

**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	1 ppm	REL-TWA	0.1 ppm	TLV-TWA		PEL-TWA	1 ppm
PEL-STEL	5 ppm	REL-STEL	1 ppm	TLV-STEL		PEL-STEL	5 ppm
PEL-C		REL-C		TLV-C		PEL-C
Skin notation	N	Skin notation	N	Skin notation	Y	Skin notation	Y
Notes: See 29 CFR 1910.1028, Benzene. See 29 CFR 1910.1000 Table Z-2 for any operations or sectors where the exposure limits in 1910.1028 are stayed or otherwise not in effect.		Notes: CARCINOGEN (Ca): REDUCE EXPOSURE TO LOWEST FEASIBLE CONCENTRATION. See Appendix A, NIOSH Potential Occupational Carcinogens.		Notes: Visit the ACGIH TLV site for specific data BEI®		Notes: Also See California Code of Regulations, Title 8, Sec 5218.
Health factors: See NIH-NLM PubChem.		IDLH	500 ppm
Carcinogenic classifications: EPA-A; K, IARC-1, NIOSH-Ca, NTP-K, OSHA-Ca, TLV-A1		Notes: Ca
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3: 50 ppm/150 ppm/1000 ppm

Additional Resources and Literature References

NOAA: CAMEO Chemicals - Benzene

NIOSH: Pocket Guide to Chemical Hazards - Benzene

Literature References

ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Benzene. See annual publication for most recent information.
Occupational Health Guidelines for Chemical Hazards. DHHS/ NIOSH Publication No. 81-123, (January 1981).
EPA: Hazard Summary - Benzene.
ATSDR: Toxicological Profile for Benzene. 2007.
ANSI Z37.4, Acceptable Concentrations of Benzene.
Costatini AS, et al. Exposure to benzene and risk of breast cancer among shoe factory workers in Italy. Tumori. 95(1):8-12, January-February 2009.
Ji Z, et al. Comparison of aneuploidies of chromosomes 21, X, and Y in the blood lymphocytes and sperm of workers exposed to benzene. Environ Mol Mutagen. 53(3):218-26, April 2012.
Lupo PJ, et al. Maternal exposure to ambient levels of benzene and neural tube defects among offspring: Texas, 1999-2004. Environ Health Perspect. 119(3):397-402, March 2011.
Marchetti F, et al. Occupational exposure to benzene and chromosomal structural aberrations in the sperm of Chinese men. Environ Health Perspect. 120(2):229-34, February, 2012.
Peplonska B, et al. Occupational exposure to organic solvents and breast cancer in women. Occup Environ Med. 67(11):722-9, November, 2010.
Prochazka M, et al. Occupational exposures and risk of acoustic neuroma. Occup Environ Med. 67(11):766-71, November, 2010.

Last Updated Date : 04/02/2024

Group Sampling Information
Sampling Media	Sampling Time (If there are exceptions they will be in Notes)	TWA Sampling Volume (If there are exceptions they will be in Notes)	TWA Flow Rate (If there are exceptions they will be in Notes)
CSC Tube (100/50 mg sections, 20/40 mesh), [SKC 226-01]	240 min	12 L	0.05 L/min

Analytes Sampling Information
Analytes	IMIS Code	Wipe Sampling
Isobutyl Acetate	1534	No
n-Butyl Acetate	0440	No
sec-Butyl Acetate	0441	No
tert-Butyl Acetate	0442	No
Toluene**	2460	No
Ethyl Benzene	1080	No
Perchloroethylene (Tetrachloroethylene)**	2020	No
Trichloroethylene**	2490	No
Xylene	2590	No
Trimethylbenzene	2505	No
Benzene***	0320	No
Ethyl Acetate****	1040	No
n-Propyl Acetate‡	2180	No
Pentane‡‡	1990	No
Cyclohexane‡‡‡	0810	No
Heptane*	1371	No
n-Hexane‡‡‡‡	1380	No
Nonane*	N807	No
Octane*	1957	No

Notes

Request any (up to three (3)) of these analytes together.

Alternatively request IMIS Code Q115 and SLTC will report any significant amounts of these analytes.

Results for unrequested analytes in this group will be reported if significant amount are found.

Toluene, sec-Butyl Acetate, Benzene and Isobutyl Alcohol all have/are known interferences. Please indicate on the 91A which of these compounds are known to be present.

There is no need to contact SLTC before sampling.

*80 min (4L)

**Peak sampling 1 min (0.05 L) and Ceiling sampling 5 min (0.25 L)

***STEL sampling 15 min (0.75 L)

****120 min (6 L)

‡200 min (10 L)

‡‡45 min (2.25 L)

‡‡‡190 min (9.5 L)

‡‡‡‡98 min (4.9 L)

BENZENE‡

Chemical Identification

Physical Properties

Monitoring Methods Used by OSHA

Bulk/Wipe Method

On-Site Screening Techniques

Exposure Limits

Additional Resources and Literature References