Label abbreviations descriptions

METHYL BROMIDE†

Chemical Identification
CAS # 74-83-9
Formula

CH₃Br
Synonyms

bromomethane; monobromomethane

Physical Properties
Physical description Colorless gas with a chloroform-like odor at high concentrations.
Boiling point 38°F Molecular weight 94.95
Freezing point/melting point -137°F Vapor pressure 1.9 atm
Flash point Vapor density 3.36
Specific gravity 1.73 (liquid at 32°F) Ionization potential 10.54 eV
Lower explosive limit (LEL) 10% Upper explosive limit (UEL) 16%
NFPA health rating 3 NFPA fire rating 1
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.) 1680
Sampling group
Sampler/Sampling media 2 Anasorb 747 sampling tubes (6 mm glass tubes, the front tube contains 400 and the back 200 mg of sorbent) connected in series [SKC 226-82], tube holder [SKC 222-3L-1], Type D cover [SKC 224-29D]
Sampling time*

60 min
Sampling volume (TWA)*

3 L
Sampling flow rate (TWA)*
 

0.05-0.2 L/min
Sampling volume (STEL/Peak/C)*
 

3 L
Sampling flow rate (STEL/Peak/C)*
 

0.05-0.2 L/min
Analytical method instruments GC-FID
Method reference OSHA PV2040 (partially validated)
Notes
 

The Anasorb tubes should be separated and capped after sampling. Tubes should be refrigerated as soon after sampling as possible and shipped cold to the SLTC. 
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
Model/Type Gastec 136LA Matheson-Kitagawa 8014-157SB
Sampling information
(see manufacturer instructions) 		1-2 strokes, 0.2-36 ppm range, uncertainty 16% for 1-6 ppm, 8% for 6-18 ppm 1,2 or 4 strokes, approx 0.2-80 ppm rang

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
 
 

1 ppm [1994]

 PEL-TWA
 
 

1 ppm (3.88 mg/m³)
PEL-STEL
 

 

 REL-STEL
 
 

 

 TLV-STEL
 
 

 

 PEL-STEL
 
 

 
PEL-C
 

20 ppm (80 mg/m³)

 REL-C
 
 

 

 TLV-C
 
 

 

 PEL-C
 
 

20 ppm
Skin notation
 
 

Y

 Skin notation
 
 

N

 Skin notation
 
 

Y

 Skin notation
 
 

Y
Notes:
 
 

See 29 CFR 1910.1000 Table Z-1.

 Notes:
 
 

CARCINOGEN (Ca): REDUCE EXPOSURE TO LOWEST FEASIBLE CONCENTRATION (LOQ 4.7 ppm). See Appendix A, NIOSH Potential Occupational Carcinogens. See also Appendix G: 1989 Air Contaminants Update Project - Exposure Limits NOT in Effect

 Notes:
 
 

 

 Notes:
 
 

 
Health factors:  See NIH-NLM PubChem. IDLH
 

250 ppm

 

 
Carcinogenic classifications: IARC-3, NIOSH-Ca, TLV-A4, EPA-D Notes:
 
 

Ca
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:
 
 

--/50 ppm/200 ppm

Additional Resources and Literature References

Last Updated Date : 01/29/2021