Alan Buckley
University of British Columbia Vancouver
Potential Hazards Involved in Using Dimethyl Sulfoxide
Although first synthesized in 1867, dimethylsulfoxide (DMSO) has come into prominence as a solvent only in recent years. It has a high dielectric constant (45 a t 25')' and very pronounced solvation properties. Because of these, and other properties a wide range of reactions has been studied in DMS0.2 As is the case with many organic solvents, contact with DMSO tends to dehydrate and de-fat the skin. Apart from this, DMSO itself seems to he relatively free from toxic side-effects. All reported studies indicate that DMSO has a low acute mammalian toxicity similar to that of e t h a ~ o l . ~ It is when solutions of compounds in DMSO are used that a haaadous element is introduced in handling. The wide potential uses of DMSO in therapeutic treatment fall into two main groups; the analgesic properties of DMSO itself which do not concern us here, and absorption of pharmacologically active compounds, dissolved in DMSO, through the skin-this latter property of DMSO creates a potential hazard. Jacob, Bischel, and Herschler4 have reported that when DMSO, or solutions in DMSO, are applied to tissues, penetration is rapid through all body membranes tested and that in many cases the solute is also carried through the membranes. It can be seen that any compound (e.g. aniline) which is deleterious to health by absorption through the skin is potentially much more hazardous when in solution in DMSO. Herschler and Jacob4 have reported such a case. Workers using DMSO solutions of organophosphorus insecticides suffered temporary toxic effectsdue to the cholinesterase inhibiting action of such compounds, even though they were wearing synthetic rubber 'SCHLAFER, H. L.,
AND
SHAFFERNICHT, W., Angew. Chem.,
72, 618 (1960).
'See especially '"DMSO-Reaction Medium and Reactant," Crown Zellerbaeh Corporation. Camas, Washington. "HERSCHLER. R. J.. AND JACOB. S. W.. J . Tech. Assoc. Pulp and Paper Ind., 4 8 . ~ 0 6'(1965), . 43~. 'JACOB, 8. W., BISCHEL, M., AND HERSCHLER, R. J., CUTT& Therapeutic Res., 6 , No. 3, 193 (1964).
674 / Journal of Chemical Education
gloues. Experiments with test animals support this o b s e ~ a t i o n . ~Many compounds which are known to he toxic (mercuric salts, metal cyanides, etc.=) and many more which are potentially toxic (aromatic amines, pheuylhydrazones etc.) are soluble in, and used in, DMSO. An additional hazard may be introduced in handling such solutions which is not present when such solutes are used in other solvents. If such a solution is spilled on the skin it should he immediately washed well with water.
