Dimethylformamide hazards

Toxins have been dissolved in solvents to facilitate handling, to stabilize them, or to create a percutaneous hazard. Percutaneous enhancement solvents include dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylpalmitamide, N,N-dimethyldecanamide, and saponin. Color and other properties of these solutions may vary from the pure agent. Odors will vary depending on the characteristics of the solvent(s) used. 

Note Phosgene is eery hazardous and only professional chemists working with a fume hood should even think about using this method. It can be dissolved in a weighed container of DMF (dimethylformamide) and a second weighing will give the phosgene concentration. 

This group tends to react violently with protic organic solvents, water, and the aprotic solvents, dimethylformamide and dimethyl sulfoxide. Their facile reaction with ethers is also potentially hazardous. 

Dimethylformamide — Fire Hazards Flash Point (deg. F) 153 OC 136 CC Flammable Limits in Air (%) 2.2 -15.2 Fire Extinguishing Agents Water, foam carbon dioxide, or dry chemical Fire Extinguishing Agents Not to be Used Not pertinent Special Hazards of Combustion Products ... 

Capello et al.16 applied LCA to 26 organic solvents (acetic acid, acetone, acetonitrile, butanol, butyl acetate, cyclohexane, cyclohexanone, diethyl ether, dioxane, dimethylformamide, ethanol, ethyl acetate, ethyl benzene, formaldehyde, formic acid, heptane, hexane, methyl ethyl ketone, methanol, methyl acetate, pentane, n- and isopropanol, tetrahydrofuran, toluene, and xylene). They applied the EHS Excel Tool36 to identify potential hazards resulting from the application of these substances. It was used to assess these compounds with respect to nine effect categories release potential, fire/explosion, reaction/decomposition, acute toxicity, irritation, chronic toxicity, persistency, air hazard, and water hazard. For each effect category, an index between zero and one was calculated, resulting in an overall score between zero and nine for each chemical. Figure 18.12 shows the life cycle model used by Capello et al.16... 

Although somewhat difficult to purify, acetonitrile is stable on storage after purification. It is toxic, with a maximum recommended limit of 40 ppm,79 and the vapor pressure is sufficient for this to be a hazard. Its high volatility makes the removal of solvent by evaporation easy (e.g., workup of a reaction mixture for product identification). Both radical cations and anions react with traces of wate r in acetonitrile, and, because it does not hydrogen-bond to water as do dimethyl sulfoxide and dimethylformamide, radical anions generally have a... 

Hazards Wear gloves when handling concentrated sulfuric acid, and use caution. Ethyl alcohol, dimethylformamide, and ether are highly flammable. Ether can form explosive mixtures with sir, so use caution and extinguish all sources of ignition. 

SAFETY PROFILE Moderately toxic by skin contact, inhalation, intravenous, and intraperitoneal routes. Mildly toxic by ingestion. Experimental teratogenic and reproductive effects. A skin and eye irritant. Less toxic than dimethylformamide. Mutation data reported. Combustible when exposed to heat and flame. A moderate explosion hazard. Violent reaction with halogenated compounds (e.g., carbon tetrachloride, hexachlorocyclohexane) when heated above 90°C. Iron powder catalyzes the reaction so that it initiates at 71 °C. 

Cleaning Up The filtrate and washings fi om this reaction are dark, oily, and smell bad. The mixture contains dimethylformamide and could contain traces of all starting materials. Keep the volume as small as possible and place it in the hazardous waste container for organophosphorus compounds. If methylcyclohexane was used for recrystallization, place the mother liquor in the organic solvents container. 

Hazard Reacts with water to evolve hydrogen and sodium hydroxide. Flammable, dangerous fire risk. Store out of contact with moisture. Note An explosion can occur by spontaneous ignition of the gases released from a saturated solution of sodium borohydride in dimethylformamide at 17C. 

Salts of the brown-black [Co(en)2(SCH2CH2NH2)]2 are stable indefinitely in air and are stable for days in solutions of dilute aqueous acid at moderate (60°) temperatures. The solid perchlorate salt will ignite in a Bunsen burner flame or on contact with a hot surface, but presents no hazard in solution. The perchlorate salt is the most soluble of those listed above, being very soluble in H20 (0.4 M at 25°),s TVJV-dimethylformamide (DMF), and dimethyl sulfoxide, soluble in triethyl phosphate, methanol, and tetrahydrothiophene 1,1-dioxide... 

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