December 1, 1999

Product Data Sheet

Percap™ 355
LP-Gas Odorant Grade Ethyl Mercaptan

Physical Properties

Product Quality

Boiling Point: 

95oF (35oC)

Vapor Pressure: 

16.4 psia @ 100oF (38oC)
 

23.8 psia @ 120oF (49oC)
 

33.8 psia @ 140oF (60oC)

Evaporation Rate: 

<1 (ethyl ether = 1)

Chemical Stability: 

Stable

Freezing Point: 

-234oF (-148oC)

Solubility in Water: 

1.478 wt% @ 77oF (25oC)

Viscosity (liq): 

0.286 Centipoise @ 77oF (25oC)

Spec. Gravity (liq): 

0.833 (water = 1) @ 77oF (25oC)

Density (liq): 

6.95 lbs/gal @ 77oF (25oC)
   

Formula: 

C2H5SH

Synonyms: 

Ethyl mercaptan
 

Ethanethiol

CAS Number: 

75-08-1

Molecular Weight: 

62.1 (avg)

Volatiles: 

100 wt%

Form: 

Clear liquid

Color: 

Water white

Cloud Point: 

-50oF max

Corrosion: 

Negative (copper strip)
   
   

Exposure Limits

Flammability

PEL (OSHA): 

10 ppm, 25 mg/m3, Ceiling

TLV (ACGIH): 

0.5 ppm, 1.3 mg/m3, 8 Hr. TWA

Flammable limits in Air: 

LEL = 2.8 vol%
 

UEL = 18.0 vol%

Flash Point: 

-55oF (48oC)

Autoignition: 

570oF (299oC)

Analysis of Composition (wt%)

Material

Minimum

Typical

Maximum

Ethyl mercaptan:

98.5

>99

100

Related sulfides:

0.0

<1

1.5

Others:

0.0

<0.01

0.1

Rate of Odorization

The National Fire Association in their publication NFPA 58 states that experience has shown that ethyl mercaptan in the ratio of 1.0 lb per 10,000 gallons of LPG has been recognized as an effective odorant.  This ratio will make LPG vapors detectable by an average sense of smell before the concentration in air exceeds one-fifth the lower limit of flammability.  Many companies use a ratio of 1.5 lbs per 10,000 gallons as an additional safety measure.  Contact AdSpec for more information.

The information provided by AdSpec is supplied free of charge and is based on data AdSpec believes to be reliable.  It is intended for use by persons having technical skill and at their own discretion and risk.  Since conditions of use are outside our control, AdSpec makes no warranties on this information or on Percap™ 355 performance, express or implied, and assumes no liability in connection with use thereof.

Copyright © 1998
Advanced Specialty Chemicals Co., LC
320 South 29th Street, P.O. Box 310
Blackwell, Oklahoma 74631 U.S.A.
(580) 363-0000