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General Description

Synonyms: DMSO; Deltan; Methyl sulfoxide; Demeso; Demasorb; DMS-90; DMS-70

OSHA IMIS Code Number: D139

Chemical Abstracts Service (CAS) Registry Number: 67-68-5

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: PV6210000

Chemical Description and Physical Properties:

colorless hygroscopic liquid
molecular weight: 78.1
vapor pressure: 0.049 kPa at 20°C
molecular formula: C2H6OS
boiling point: 189°C
melting point: 18.5°C
flash point: 87°C closed cup, 95°C open cup

Incompatibilities: Reacts violently with strong oxidants such as perchlorates

Health Factors

Potential Symptoms: Irritation of eyes and skin; headache; nausea; blurred vision; dry skin; INGES. ACUTE: Nausea, vomiting; drowsiness; SKIN ABS

Health Effects: Irritation-Eyes---Marked (HE14); Irritation-Skin---Mild (HE16); Narcosis (8)

Affected Organs: Eyes, skin, respiratory system


  1. OSHA does not have a PEL for dimethyl sulfoxide (DMSO).
  2. Vapor/air mixtures of DMSO may be explosive at temperatures above 87°C.
  3. DMSO is listed by the FDA as a substance that is permitted for direct addition to food for human consumption as a residual solvent at not more than 2 ppm in sucrose fatty acid esters (21 CFR 172.859). It also is approved by the FDA for the intravesical treatment of interstitial cystitis (painful bladder syndrome).
  4. The 24-hr urinary excretion of DMSO and its metabolites, dimethylsulfone and dimethylsulfide, averaged 44%, 4.0% and 3.5%, respectively, in patients receiving intravenous infusions of stem cells that had been cryopreserved in 10% DMSO.
  5. Dimethylsulfide production from sewage contaminated with DMSO was reported to be responsible for a "rotten cabbage" odor that plagued a Philadelphia neighborhood near a sewage treatment plant.
  6. The estimated half-life of DMSO in serum from two volunteers given radiolabled DMSO (1 g/kg) dermally (n=2) or orally (n=6) was 11-14 hours and 20 hours, respectively. The corresponding half-lives in serum of dimethylsulfone were 60-70 hours and 72 hours, respectively.
  7. In vitro, 0.1, 1 and 2% dimethyl sulfoxide caused a concentration-related inhibition of the activities of cytochrome P-450s in human hepatocytes (in order of decreasing inhibition): 2E1 > 2C19 > 2C9 > 3A4.

Literature Basis:

  • International Chemical Safety Cards (WHO/IPCS/ILO): Dimethylsulphoxide.
  • Easterbrook, J., Lu, C., Sakai, Y. and Li, A.P.: Effects of organic solvents on the activities of cytochrome P450 isoforms, UDP-dependent glucuronyl transferase, and phenol sulfotransferase in human hepatocytes. Drug. Metab. Dispos. 29(2): 141-144, 2001.
  • Egorin, M.J., Rosen, D.M., Sridhara, R., Sensenbrenner, L. and Cottler-Fox, M.: Plasma concentrations and pharmacokinetics of dimethylsulfoxide and its metabolites in patients undergoing peripheral-blood stem-cell transplants. J. Clin. Oncol. 16(2): 610-615, 1998.
  • Glindemann, D., Novak, J. and Witherspoon, J.: Dimethyl sulfoxide (DMSO) waste residues and municipal waste water odor by dimethyl sulfide (DMS): the north-east WPCP plant of Philadelphia. Environ. Sci. Technol. 40(1): 202-207, 2006.
  • Hucker, H.B., Miller, J.K., Hochberg, A., Brobyn, R.D., Riordan, F.H. and Calesnick, B.: Studies on the absorption, excretion and metabolism of dimethylsulfoxide (DMSO) in man. J. Pharmacol. Exp. Ther. 155(2): 309-317, 1967.
  • Pohanish, R.P. (editor): Dimethyl Sulfoxide. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 942-943.
  • Rossberger, J., Fall, M. and Peeker, R.: Critical appraisal of dimethyl sulfoxide treatment for interstitial cystitis: discomfort, side-effects and treatment outcome. Scand. J. Urol. Nephrol. 39(1): 73-77, 2005.

Date Last Revised: 03/14/2007

Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):

  • sampling media: Charcoal Tube (100/50 mg sections)
    analytical solvent: (95:5) Methylene Chloride:Methanol
    maximum volume: 10 Liters
    maximum flow rate: 0.1 L/min
    current analytical method: Gas Chromatography; GC/FID
    method reference: OSHA Salt Lake Technical Center In-House File
    method classification: Not Validated

Conditions: Column: 60 m X 0.32mm id Stabilwax 1 u film; Oven: 60°C for 5 min then 10°/min to 200°C; Inj: 200; Det: 250°C; Retention Time: DMSO 22.37 min

Articles: An in house study using both silica gel and Tenax GC adsorbent for collection of DMSO indicated that neither was acceptable. Desorption efficiency from silica gel was only 75% and the storage stability for Tenax GC was 79% after only three days.

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