Dimethyl sulfate

  • Sulfuric acid, dimethyl ester
  • Dimethyl monosulfate
  • DMS
Formula (CH3)2SO4
Structure
Description Colorless, oily liquid, faint onion odor.
Uses Formerly as war gas, manufacture of dyes, colors, perfumes, solvent for separation of mineral oils, analysis of auto fluids.

Registry Numbers and Inventories.
CAS 77-78-1
EC (EINECS/ELINCS) 201-058-1
EC Index Number 016-023-00-4
EC Class Carcinogenic Category 2; Mutagenic Category 3; Very toxic; Toxic; Corrosive; Sensitising
EC Risk Phrase R 45 E25 E26 34 43 68
EC Safety Phrase S 53 45
RTECS WS8225000
RTECS class Tumorigen; Mutagen; Reproductive Effector; Human Data; Primary Irritant
UN (DOT) 1595
Merck 12,3305
Beilstein/Gmelin 635994
Beilstein Reference 4-01-00-01251
RCRA U103
Swiss Giftliste 1 G-1564
Canada DSL/NDSL DSL
US TSCA Listed
Austrailia AICS Listed
New Zealand Listed
Japan ENCS (MITI) Listed
Korea ECL Listed

Properties.
Formula C2H6O4S
Formula mass 126.13
Melting point, °C -31.8
Boiling point, °C 189
Vapor pressure, mmHg 0.85 (25 C)
Vapor density (air=1) 4.35
Saturation Concentration 660 ppm (0.06%) at 20 C (calculated)
Density 1.349 g/cm3 (0 C)
Solubility in water 28 g/L
Surface tension 40.12 g/s2 (18 C)
Refractive index 1.3861 (15.8 C)
Partition coefficient, pKow 0.08
Heat of vaporization 40.7 kJ/mol

Hazards and Protection.
Storage Keep away from sources of ignition. Store in a cool, dry place. Store in a tightly closed container. Corrosives area. Do not store in metal containers.
Handling Wash thoroughly after handling. Wash hands before eating. Remove contaminated clothing and wash before reuse. Use only in a well ventilated area. Do not get in eyes, on skin, or on clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Do not ingest or inhale. 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 Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.
Small spills/leaks Absorb spill with inert material, (e.g., dry sand or earth), then place into a chemical waste container. Clean up spills immediately, using the appropriate protective equipment. Scoop up with a nonsparking tool, then place into a suitable container for disposal. Provide ventilation.
Disposal code 9
Stability Stable under normal temperatures and pressures.
Incompatibilities Strong oxidizing agents, strong bases, ammonia, and moist air or water. Can react violently with ammonium hydroxide and sodium azide.
Decomposition Carbon monoxide, oxides of sulfur, irritating and toxic fumes and gases, carbon dioxide.

Fire.
Flash Point,°C 83
Autoignition, °C 450
Upper exp. limit, % 23.2
Lower exp. limit, % 3.6
Fire fighting Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Use water spray to keep fire-exposed containers cool. Containers may explode in the heat of a fire. Combustible Liquid. Contact with metals may evolve flammable hydrogen gas. To extinguish fire, use water, dry chemical, chemical foam, or alcohol-resistant foam. For small fires, use dry chemical, carbon dioxide, sand, earth, water spray or regular foam. Cool containers with flooding quantities of water until well after fire is out.
Fire potential Moderately flammable. Requires moderate heating.
Hazards Material is normally stable even under fire exposure conditions and is not hazardously reactive with water. It is incompatible with strong oxidizers and strong ammonia solutions.
Combustion products Combustion may produce irritants and toxic gases.
NFPA Health 4
  Flammability 2  
  Reactivity 1  

Health.
Exposure limit(s) OSHA PEL: TWA 1 ppm (5 mg/m3) skin NIOSH REL: Ca TWA 0.1 ppm (0.5 mg/m3) skin See Appendix A NIOSH IDLH: Potential occupational carcinogen 7 ppm
Carcinogin G-A3, I-2A, N-2, CP65
Poison_Class 1*
Exposure effects May cause liver and kidney damage. May cause cancer in humans. May cause reproductive and fetal effects.
   Ingestion Harmful if swallowed. Causes gastrointestinal tract burns. Effects may be delayed 2 to 4 hours.
   Inhalation May be fatal if inhaled. Effects may be delayed. Causes severe irritation of upper respiratory tract with coughing, burns, breathing difficulty, and possible coma. May cause lung damage. Inhalation may be fatal as a result of spasm, inflammation, edema of the larynx and bronchi, chemical pneumonitis and pulmonary edema.
   Skin Causes skin burns.
   Eyes Causes eye burns. May cause irreversible eye injury.

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 not breathing, give artificial respiration. If breathing is difficult, give oxygen. DO NOT use mouth-to-mouth respiration.
   Skin Get medical aid immediately. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse. Destroy contaminated shoes.
   Eyes Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately.

Transport.
UN number 1595
Response guide 156
Hazard class 6.1
PRTC T
Packing Group I  
USCG CHRIS Code DSF  
USCG Compatatibility Group 34 Esters
HS Code 2920 90 10  
Std. Transport # 4921405