BACKGROUND Organic diisocyanates are a common cause of occupational asthma, particularly in motor vehicle repair (MVR) workers. The UK Health & Safety Laboratory provides screening for urinary hexamethylenediamine (UHDA), a biomarker of exposure to 1,6-hexamethylene diisocyanate (HDI). The UK Surveillance of Work-related and Occupational Respiratory Disease scheme (SWORD) has collected reports ...

The determination of isocyanates concentrations in air is complicated by thepresence of these substances as monomers and oligomers as well as in thevapor and aerosol phases. Direct-reading instruments (DRIs) are available fordetermining the diisocyanate concentrations in workplace air, but they arecalibrated for the monomers only. Industry uses polymeric diisocyanateswhich c...

BACKGROUND Two outbreaks of allergic contact dermatitis caused by isocyanates at two companies in southern Sweden initiated a research project focusing on contact allergy to isocyanates. Within the project, there was an interest in determining how often contact allergy to the most common isocyanate, diphenylmethane-4,4'-diisocyanate (4,4'-MDI), occurred. OBJECTIVES To determine and compare th...

In recent year, biocompatible, biodegradable materials (linear polylactic acid-based urethanes) in the solid and/or liquid form have attracted tremendous attention in biomedical application particularly in stent coating. Low molecular weight poly (lactic acid) s (PLA), having narrow molecular weight distribution was by dehydropolycondensation method using tetraphenyltin as a catalyst. Hydroxyl ...

Isocyanates 7 were formed from monoprotected diamines 3 or 6, which in turn can be easily prepared from commercially available N-BOCor N-FMOC-protected amino acid derivatives. Isocyanates 7, formed in situ, could be coupled directly to a solid support functionalized with amine groups or to amino acids anchored on resins using CH2Cl2 as solvent and an 11 h coupling time at 25 °C. Such couplings ...

Lungs comprise the primary organ exposed to environmental toxic chemicals, resulting in diverse respiratory ailments and other disorders, including carcinogenesis. Carcinogenesis is a multi-stage phenomenon, which involves a series of genetic alterations that begin with genomic instability provoked by certain factors such as inflammation and DNA damage and end with the development of cancer. Is...

OBJECTIVE Isocyanates (di- and poly-), important chemicals used worldwide to produce polyurethane products, are a leading cause of occupational asthma. Respiratory exposures have been reduced through improved hygiene controls and the use of less-volatile isocyanates. Yet isocyanate asthma continues to occur, not uncommonly in settings with minimal inhalation exposure but opportunity for skin ex...