Trimethylbenzene Fact Sheet

Source of Exposure

Trimethylbenzenes are used as solvents and intermediates for chemical synthesis, manufacture of paint thinners, perfumes, dyes, and as motor fuel additive. Inhalation is the major route of exposure, though trimethylbenzene can be absorbed through the skin. This compound has been found to be present in the exhaust of diesel engines.

Symptoms

The effects of trimethylbenzene are similar to other aromatic solvents. Exposure can cause conjunctivitis, headaches, fatigue, nausea, and narcosis. Direct contact with the liquid can cause skin irritation, chemical pneumonitis, and asthmatic bronchitis. Exposure may also produce behavioral changes such as nervousness, tension, and anxiety. Leucopenia and thrombocytopenia have been reported in experiments with laboratory animals.

Blood Concentrations

Data shows that the general population has whole blood levels of trimethylbenzene of less than 1.0 PPB. (EHS data) The Threshold Limit Value for Trimethylbenzene has been set at 25,000 PPB in ambient air. Currently, no studies exist which determine the corresponding blood levels for workers exposed at this air concentration.

Toxic Levels

Information on the toxic effects of trimethylbenzene is limited. There are no conclusive examples that clearly define the blood levels of trimethylbenzene which cause symptoms to develop. Individuals who have been sensitized may manifest negative health effects at concentrations well within the ranges considered safe for the average population. (See Chemically Sensitive Patients.)

Metabolism

Information on the metabolism of trimethylbenzene is limited and unclear at the present time. This information will be updated as further research is published.

Summary

Classification: Aromatic Solvent
Population Average: < I PPB (whole blood)
Threshold Limit Value: 25,000 PPB (air)
Onset of Symptoms: Data not available
Death: Data not available
Half Life: Data not available
LD 5O: (interperitoneal - rat) 2 g/kg 1500 mg/kg

References

-Alessio, L., Berlin, A., Roi, R., and Boni, M. (Eds.) Human biological monitoring of industrial chemicals series, Luxemberg, Commission of European Communities, 1983.

-Baselt, R.D. Disposition of Toxic Drugs and Chemicals in Man, 2nd Ed., Davis, CA: Biomedical Publications, 1982.

-Clayton, G.D. and Clayton, F.E., Patty's Industrial Hygiene and Toxicology, vol. 2B, 3rd ed., Wiley-Interscience, New York, 1981.

-Doull, J. et al., Casarett and Doull's Toxicology, 2nd ed., Macmillan, New York, 1980.

-Last, J.M., Maxcy-Rosenau Public Health and Preventive Medicine, 11th ed., Appleton-Century-Crofts, New York, 1980.

-Plunkett, E.R., Handbook of Industrial Toxicology, Chemical Publishing Co., New York, 1976.

-Sax, N.I., Ed., Dangerous Properties of Industrial Materials Report, 6th Ed., New York, Van Nostrand Reinhold Co., 1984.

-Seba, D. B. , Mi lam, M. J. and Laseter , J. L. "Uptake, measurement and elimination of synthetic chemicals by man", in Brostoff, J . and Challacombe, S.J. (Eds) Food Allergy and Intolerance, London: Bailliere Tindall, 1987.