METHYL SILICATE†

Chemical Identification

CAS # 681-84-5
Formula
 

C₄H₁₂O₄Si

Synonyms
 

methyl orthosilicate; tetramethoxysilane; tetramethyl ester of silicic acid; tetramethyl silicate

Physical Properties

Physical description Clear, colorless liquid.
Boiling point 250°F Molecular weight 152.3
Freezing point/melting point 28°F Vapor pressure 12 mmHg at 77°F
Flash point 205°F Vapor density
Specific gravity 1.02 Ionization potential
Lower explosive limit (LEL) Upper explosive limit (UEL)
NFPA health rating 3 NFPA fire rating 3
NFPA reactivity rating 1 NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs

Monitoring Methods Used by OSHA

Analyte code (IMIS no.)
Sampling group
Sampler/Sampling media
Sampling time*
Sampling volume (TWA)*
Sampling flow rate (TWA)*
Sampling volume (STEL/Peak/C)*
Sampling flow rate (STEL/Peak/C)*
Analytical method instruments
Method reference
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
 

1 ppm (6 mg/m³)

TLV-TWA
 

1 ppm [1978]

PEL-TWA
 

1 ppm (6 mg/m³)

PEL-STEL
 

 

REL-STEL
 

 

TLV-STEL
 

 

PEL-STEL
 

 

PEL-C
 

5 ppm (30 mg/m³)

REL-C
 

 

TLV-C
 

 

PEL-C
 

 

Skin notation
 

N

Skin notation
 

N

Skin notation
 

N

Skin notation
 

N

Notes:
 

The OSHA PEL applies to Construction and Maritime Industries only. See 29 CFR 1926.55 Table 1 and 29 CFR 1915.1000 Table Z-Shipyards.

Notes:
 

 

Notes:
 

 

Notes:
 

 

Health factors:  See NIH-NLM PubChem. IDLH
Carcinogenic classifications: Not listed Notes:
 

 

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

--/10 ppm/20 ppm

Additional Resources and Literature References

Last Updated Date : 06/01/2022