Dimethyl sulfate, an organic compound, a colorless or slightly yellow, oily flammable liquid with a slight onion odor. It is easily hydrolyzed into sulfuric acid and methanol at 50°C or alkaline water. Decomposes slowly in cold water. It is combustible when exposed to heat, open flame or oxidant. Dimethyl sulfate is a reagent that can methylate DNA. After methylation, DNA can be degraded at the methylated position.
Main purpose
Used in the manufacture of dyes and as a methylating agent for amines and alcohols. Analysis reagents. Organic synthesis, methylating reagents. Solvent. Its vapor is highly toxic and has been used as a war gas. Used as a reagent for the determination of coal tar, and as a methyl substitution agent in organic synthesis.  
PropertiesPhysical Chemistry
Colorless or slightly yellow, oily flammable liquid with a slight onion odor. The molecular weight is 126.14. The relative density is 1.3322 (20℃/4℃). Melting point-31.8 ℃. Boiling point: 188℃/ring opening. The flash point is 83.33°C. The self-ignition point is 187.78℃. The vapor density is 4.35. The vapor pressure is 2.00kPa (15mmHg 76°C). Soluble in ethanol and ether, solubility in water is 2.8g/100ml. It is easily hydrolyzed into sulfuric acid and methanol at 50°C or alkaline water. Decomposes slowly in cold water. It is combustible when exposed to heat, open flame or oxidant.
Combustion products: carbon monoxide, carbon dioxide, sulfur dioxide.
Waste disposal
Use incineration. The waste materials are diluted and neutralized and then incinerated, and the sulfur oxides discharged from the incinerator are removed by the scrubber.
Laboratory destruction
In the laboratory, it can be diluted and then destroyed by ammonia water. The reaction produces less toxic methylamine, dimethylamine and other substances.
Fire fighting method
Firefighters must wear gas masks and full-body firefighting suits. Extinguishing agent: water mist, carbon dioxide, foam, sand.
Invasion method
It is mainly inhaled through the respiratory tract, but can also be inhaled through the skin.
First aid treatment
First, quickly rescue the poisoned patient to a place with fresh air, remove contaminated clothes, thoroughly clean the skin, observe the irritation response for at least 24 to 48 hours, inhale oxygen in time, and give symptomatic treatment such as sedation, expectorant and antispasmodic drugs. When the site is contaminated, rinse thoroughly with normal saline or water as soon as possible, then rinse with 5-10% sodium bicarbonate solution, and then use cortisone and antibiotic eye drops alternately. Early, moderate, and short-term glucocorticoid therapy can be used. Effectively prevent pulmonary edema. Anti-infection and exposure or desensitization therapy is used for skin burns. We must always be alert to the occurrence of delayed poisoning effects.
Patients with poisoning should absolutely stay in bed, keep quiet, and observe the condition closely. Emergency treatment includes reasonable oxygen inhalation, bronchial relievers and antitussives and expectorants. The application of adrenal glucocorticoids should be early, appropriate, and short-term; antibiotics should be given early, and sedatives can be given if necessary.
Dimethyl sulfate is used as a methylating reagent in organic chemistry. However, with the in-depth research on carbonates, the application range of dimethyl sulfate is getting smaller and smaller, and it is believed that it will be completely replaced by non-toxic carbonates in the near future.
Leakage emergency response
Quickly evacuate personnel from the contaminated area to a safe area, and immediately isolate them for 150 meters, strictly restricting access. Cut off the fire source. It is recommended that emergency response personnel wear self-contained positive pressure respirators and anti-virus suits. Do not directly touch the leakage. Cut off the source of leakage as much as possible to prevent entry into restricted spaces such as sewers and flood drains. Small leakage: absorb with sand, vermiculite or other inert materials. A large number of leaks: construct dikes or dig pits for storage; cover with foam to reduce steam disasters. Use a pump to transfer to a tanker or a special collector for recycling or transport to a waste disposal site for disposal.
Dangerous characteristics
There is a danger of burning and explosion in contact with heat sources, open flames and oxidants. It may decompose violently in case of high heat, causing the container to rupture or explode. Reacts strongly with ammonium hydroxide.