METHYL PARATHION

Chemical Identification
Chemical Identification
CAS # 298-00-0
Formula
 

C₈H₁₀NO₅PS

Synonyms
 

azophos; O,O-dimethyl-O-p-nitrophenylphosphorothioate; parathion methyl; phosphorothioic acid O,O-dimethyl O-(p-nitrophenyl) ester

Physical Properties
Physical Properties
Physical description White to tan, crystalline solid or powder with a pungent, garlic-like odor.
Boiling point 289°F Molecular weight 263.23
Freezing point/melting point 99°F Vapor pressure 0.00001 mmHg
Flash point Vapor density 9.1
Specific gravity 1.36 Ionization potential
Lower explosive limit (LEL) Upper explosive limit (UEL)
NFPA health rating 4 NFPA fire rating 1
NFPA reactivity rating 2 NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs
Monitoring Methods Used by OSHA
Monitoring Methods Used by OSHA
Analyte code (IMIS no.) 1775
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*
 

 

Sampling volume (TWA)*
 

480 L

Sampling flow rate (TWA)*
 

1 L/min

Sampling volume (STEL/Peak/C)*
 

 

Sampling flow rate (STEL/Peak/C)*
 

 

Analytical method instruments GC-FPD
Method reference OSHA PV2112 (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.

Wipe Method
Wipe Method
Sampler/Sampling media
 

Wipe with GFF (37 mm), Type A/E [AP4003705]

Bulk Method
Bulk Method
 

Limit the amount of bulk submitted to 1 g or 1 mL.

On-Site Screening Techniques
On-Site Screening Techniques
Device
Model/Type
Sampling information
(see manufacturer instructions)
Exposure Limits
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
 

0.02 mg/m³ (inhalable fraction and vapor) [2008]

PEL-TWA
 

0.2 mg/m³

PEL-STEL
 

 

REL-STEL
 

 

TLV-STEL
 

 

PEL-STEL
 

 

PEL-C
 

 

REL-C
 

 

TLV-C
 

 

PEL-C
 

 

Skin notation
 

N

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: IARC-3, TLV-A4 Notes:
 

 

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

 

Additional Resources and Literature References
Additional Resources and Literature References

NOAA: CAMEO Chemicals - Methyl parathion

NIOSH: Pocket Guide to Chemical Hazards - Methyl parathion

Literature References

 
  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Methyl parathion. See annual publication for most recent information.

Last Updated Date : 01/05/2021