International Conference on Harmonisation; final recommendation for the revision of the permitted daily exposure for the solvent cumene according to the maintenance procedures for the guidance Q3C Impurities: Residual Solvents; availability. Notice.

The Food and Drug Administration (FDA) is announcing the availability of a final recommendation for the revision of the permitted daily exposure (PDE) for the solvent cumene according to the maintenance procedures for the guidance for industry entitled ``Q3C Impurities: Residual Solvents.'' The recommendation was prepared under the auspices of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH).

Solid phase microextraction as a short-term sampling technique for BTEX occupational exposure.

Solid phase microextraction (SPME) has been widely used for many years in various applications, such as environmental and water samples, food and fragrance analysis, or biological fluids. The aim of this study was to suggest the SPME method as an alternative to conventional techniques used in the evaluation of worker exposure to benzene, toluene, ethylbenzene, and xylene (BTEX). Polymethylsiloxane-carboxen (PDMS/CAR) showed as the most effective stationary phase material for sorbing BTEX among other materials (polyacrylate, PDMS, PDMS/divinylbenzene, Carbowax/divinylbenzene). Various experimental conditions were studied to apply SPME to BTEX quantitation in field situations. The uptake rate of the selected fiber (75 microm PDMS/CAR) was determined for each analyte at various concentrations, relative humidities, and airflow velocities from static (calm air) to dynamic (> 200 cm/s) conditions. The SPME method also was compared with the National Institute of Occupational Safety and Health method 1501. Unlike the latter, the SPME approach fulfills the new requirement for the threshold limit value-short term exposure limit (TLV-STEL) of 2.5 ppm for benzene (8 mg/m(3)).

Phenylacetylene as a new surrogate standard for the determination of BTEX by GC/FID.

Benzene, toluene, ethylbenzene, xylene (short form: BTEX) and other monoaromatic compounds are environmental contaminants which are often analyzed by GC/FID. For the calculation of BTEX concentrations in water samples normally external quantification with defined BTEX solutions is sufficient. However, for accurate quantification of BTEX in complex matrices it is necessary to use internal standards, e.g. 1-chlorohexane. Isotopes of BTEX are usually the best alternative but they are only applicable to GC/MS, because their retention times are similar to the original BTEX. 1-Chlorohexane and phenylacetylene were compared with respect to their quality as internal standards. Good results were obtained with the monoaromatic phenylacetylene as a surrogate standard. The physical properties of phenylacetylene are very similar to BTEX species and it normally does not occur in environmental samples. 1-Chlorohexane was more strongly adsorbed on the used soil than BTEX during sample preparation. This fact suggests that the single aromatic rings of BTEX and phenylacetylene are mainly responsible for the adsorption behavior.

[Exposure to organic solvent vapors during production of lacquers for automobile painting]. / Narazenie na pary rozpuszczalników organicznych podczas produkcji lakierów samochodowych.

This study was aimed at the development and improvement of the methods for determining solvent vapours to estimate occupational exposure in paint and varnish shops. Gas chromatographic method and mass spectrometry (GC-MS) were applied respectively for quantitative determination and identification of toxic substances in the work-room air in plants manufacturing carbamide car paints and commonly used phthalic paints. Particular attention was paid to aromatic hydrocarbon components of farbasol: ethyltoluenes, propylbenzene, isopropylbenzene, mesitylene, hemimelitene, pseudocumene, diethylbenzenes and cymene. These hydrocarbons constitute about 95% of farbasol. At present, the evaluation of exposure in paint and varnish factories and in paint shops in Poland is insufficient because of the lack of TLV values for the above solvents, as well as inadequate methods of determination used in majority of laboratories.