Product Identification

Product Name

DMDS

Synonyms

Methyl disulfide

CAS

624-92-0

Formula

C2H6S2

Molecular Weight

94.2

EINECS

210-871-0

RTECS

JO1927500

RTECS Class

Primary Irritant

Beilstein/Gmelin

1730824

Beilstein Reference

4-01-00-01281

EC Class

highly flammable, harmful, irritant, dangerous for the environment

Physical and Chemical Properties

Appearance

Pale yellow liquid, disagreeable odor.

Solubility in water

Slightly soluble

Melting Point

-98

Boiling Point

110

Vapor Pressure

29 (25 C)

Density

0.8483g/cm3 (20 C)

Partition Coefficient

1.77

Heat Of Vaporization

38.4 kJ/mol

Usage

As a sulfiding agent added to the initial feed of a hydrotreater when the hydrotreating catalyst is present in the form of oxides.

Vapor Density

3.24

Saturation Concentration

37600 ppm (3.8%) at 25 C (calc.)

Odor threshold

0.029 mg/m3

Refractive Index

1.5248 (20 C)

First Aid Measures

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.

Handling and Storage

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.

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.

Hazards Identification

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.

Ingestion

May cause gastrointestinal irritation with nausea, vomiting and diarrhea. May cause liver damage. May be harmful if swallowed.

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.

EC Risk Phrase

R 11 22 23 36/37/38 51/53

EC Safety Phrase

S 16 26 36/37/39 45 61

UN (DOT)

2381

Exposure Controls/Personal Protection

Personal 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.

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.

Poison Class

2

Fire Fighting Measures

Flash Point

24

Autoignition

370

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.

Upper exp. limit

16.1

Lower exp. limit

1.1

Fire Potential

HIGHLY FLAMMABLE.

Accidental Release Measures

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.

Stability and Reactivity

Disposal Code

1

Incompatibilities

Oxidizing agents, may react with copper, rubber, and plastic.

Stability

Stable under normal temperatures and pressures. Reacts vigorously with oxidizing agents. Photochemically oxidized by ozone.

Decomposition

Carbon monoxide, oxides of sulfur, irritating and toxic fumes and gases, carbon dioxide, hydrogen sulfide.

Combustion Products

Fire will produce irritating, corrosive and/or toxic gases.

Transport Information

UN Number

2381

Hazard Class

3

Packing Group

II

HS Code

2930 90 70