Dimethyl disulfide

  • Methyl disulfide
Formula
CH3SSCH3
Structure
Description
Pale yellow liquid, disagreeable odor.
Uses
As a sulfiding agent added to the initial feed of a hydrotreater when the hydrotreating catalyst is present in the form of oxides.

Registry Numbers and Inventories.
CAS
624-92-0
EC (EINECS/ELINCS)
210-871-0
EC Class
highly flammable, harmful, irritant, dangerous for the environment
R 11 22 23 36/37/38 51/53
S 16 26 36/37/39 45 61
RTECS
JO1927500
RTECS class
Primary Irritant
UN (DOT)
2381
Beilstein/Gmelin
1730824
Beilstein Reference
4-01-00-01281
Swiss Giftliste 1
G-5987
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C2H6S2
Formula mass
94.20
Melting point, °C
-98
Boiling point, °C
110
Vapor pressure, mmHg
29 (25 C)
Vapor density (air=1)
3.24
Saturation Concentration
37600 ppm (3.8%) at 25 C (calc.)
Odor Threshold Odor threshold 0.029 mg/m3
Critical temperature
340
Critical pressure
52.1
Density
0.8483g/cm3 (20 C)
Solubility in water
Slightly soluble
Viscosity
0.620 cP 20 C
Surface tension
33.6 g/s2 (20 C)
Refractive index
1.5248 (20 C)
Partition coefficient, pKow
1.77
Heat of vaporization
38.4 kJ/mol

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Keep away from sources of ignition. Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances. Flammables-area. Keep containers tightly closed.
B2 D1A D2B
Handling
Wash thoroughly after handling. Ground and bond containers when transferring material. Use spark-proof tools and explosion proof equipment. Avoid contact with eyes, skin, and clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Keep container tightly closed. Avoid contact with heat, sparks and flame. Do not ingest or inhale. Use only in a chemical fume hood. Do not pressurize, cut, weld, braze, solder, drill, grind, or expose empty containers to heat, sparks or open flames.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
Respirators
A respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use.
Small spills/leaks
Absorb spill with inert material, (e.g., dry sand or earth), then place into a chemical waste container. Use water spray to dilute spill to a non-flammable mixture. Avoid runoff into storm sewers and ditches which lead to waterways. Clean up spills immediately, using the appropriate protective equipment. Remove all sources of ignition. Absorb spill using an absorbent, non-combustible material such as earth, sand, or vermiculite. Use a spark-proof tool. Provide ventilation. A vapor suppressing foam may be used to reduce vapors. Water spray may reduce vapor but may not prevent ignition in closed spaces.
Disposal code
1
Stability
Stable under normal temperatures and pressures. Reacts vigorously with oxidizing agents. Photochemically oxidized by ozone.
Incompatibilities
Oxidizing agents, may react with copper, rubber, and plastic.
Decomposition
Carbon monoxide, oxides of sulfur, irritating and toxic fumes and gases, carbon dioxide, hydrogen sulfide.

Fire.
Flash Point,°C
24
Autoignition, °C
370
Upper exp. limit, %
16.1
Lower exp. limit, %
1.1
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Water runoff can cause environmental damage. Dike and collect water used to fight fire. Can burn in a fire, releasing toxic vapors. Will burn if involved in a fire. Use water spray to keep fire-exposed containers cool. Containers may explode in the heat of a fire. Containers may explode when heated. Extinguishing media: Water may be ineffective. Use agent most appropriate to extinguish fire. Do NOT use straight streams of water. For large fires, use water spray, fog or regular foam. For small fires, use dry chemical, carbon dioxide, water spray or regular foam.
Fire potential
HIGHLY FLAMMABLE.
Hazards
Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. May polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
Combustion products
Fire will produce irritating, corrosive and/or toxic gases.
Health
3
 
Flammability
4
 
 
Reactivity
0
 

Health.
Poison_Class
2
Exposure effects
Effects may be delayed. Exposure to high concentrations may cause lacrimation, cyanosis, central nervous system depression or hemorrhage in the lung. Prolonged or repeated exposure may cause hemolytic anemia which can lead to renal failure.
   Ingestion
May cause gastrointestinal irritation with nausea, vomiting and diarrhea. May cause liver damage. May be harmful if swallowed.
   Inhalation
May be fatal if inhaled. Vapors may cause dizziness or suffocation. Causes upper respiratory tract irritation. Exposure may cause blood abnormalities Causes irritation of the mucous membrane.
   Skin
Causes skin irritation. May cause dermatitis.
   Eyes
Causes eye irritation.

First aid
 
   Ingestion
Do NOT induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
   Inhalation
Get medical aid immediately. Remove from exposure to fresh air immediately. If breathing is difficult, give oxygen. DO NOT use mouth-to-mouth respiration. If breathing has ceased apply artificial respiration using oxygen and a suitable mechanical device such as a bag and a mask.
   Skin
Get medical aid. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid.

Transport.
UN number
2381
Response guide
Hazard class
3
Packing Group
II
 
USCG CHRIS Code
DSK
 
HS Code
2930 90 70
 
Std. Transport #
4909338
 
IMO Chemical Code
17
IMO Pollution Category
B
IMO Hazard code
S/P