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We offer biological testing services for measuring the contents of a variety of exposure markers as well as amines in clinical biological samples, with a high relevance for environmental and occupational medicine.


Isocyanates are a group of chemicals which have been used for industrial purposes for more than 50 years, mainly for manufacturing of polyurethane plastics (PUR). PUR is nowadays found in for example foam, thermoplastics, fibers, adhesives, coatings and lacquers, foils and insulation materials. Isocyanates are extremely toxic. The most critical effect of isocyanate exposure is the risk of developing isocyanate asthma. In many cases, there is also a development of hypersensitivity to air pollution and odors. Other serious effects are decreased lung function and skin allergies. Common symptoms include headache and respiratory problems such as nasal congestion, sniffing, nose bleeding or coughing. In many countries, isocyanates are subject to very low occupational exposure limits due to their hazardous properties.

This analysis can be used to determine the exposure to 4.4’-MDI, 1.5-NDI, 2.4-TDI, 2.6-TDI, 1.6-HDI, IPDI and their related diamines. Exposure to 4.4’-MDI, 1.5-NDI, 2.4-TDI, 2.6-TDI, 1.6-HDI, IPDI is determined by measuring the amounts of the related amine, i.e. 4.4’-MDA, 1.5-NDA, 2.4-TDA, 2.6-TDA, 1.6-HDA, IPDA.

Testing for exposure to diisocyanates and diamines


Benzene is naturally occurring in for example crude oil and petrol as well as cigarette smoke. It is a colorless, flammable liquid that evaporates quickly when exposed to air. The main exposure route is by inhaling air contaminated with benzene, although benzene can also be absorbed through dermal contact with benzene containing liquids. Benzene is a well-documented carcinogen. It has been established that long-term exposure to elevated levels of benzene can cause leukemia.

S-phenylmercapturic acid (S-PMA) is one of the most widely used biomarkers of benzene exposure. Since there are no other substances, exogenous or endogenous, known to be metabolized to S-PMA except benzene, the excretion of this metabolite can only be attributed to benzene exposure. The American Conference of Governmental Industrial Hygienists (ACGIH) recommends a biological exposure index (BEI®) of 25 µg/g creatinine in the end-shift urine of workers when assessing occupational exposure to benzene [1].

[1] ACGIH, Threshold Limit Values and Biological Exposure Indices, ACGIH, Cincinnati, OH, 2009.

Testing for exposure to benzene


Toluene, also known as methylbenzene, is a colorless liquid with a sweet, pungent odor. It is mainly used as a raw chemical for industrial purposes and as a solvent, but it may also be found in consumer products such as paints, glues and nail polish removers. Toluene, like benzene, also occurs naturally in crude oil. Exposure to toluene can cause skin irritation, drowsiness or dizziness, damage to the central nervous system, and is also suspected of damaging the unborn child. Exposure to toluene can be determined by analyzing the urinary excretion of S-benzyl-N-acetylcysteine (S-BMA), a widely used biomarker of toluene exposure.

Testing for exposure to toluene