The IRSST's Laboratory Division now offers an analytical determination service for respirable combustible dusts (RCDs). RCDs consist of an indicator (or tracer) for exposure to diesel particulate matter in underground mines as stipulated in the Regulation respecting occupational health and safety in mines (ROHSM, Quebec) as well as in certain other Canadian regulations. It should however be noted that RCDs are not mentioned in the Regulation respecting occupational health and safety (ROHS, Quebec).
According to the Web site of the Service du répertoire toxicologique de la CSST: "Commercial xylene is a mixture that contains variable percentages of xylene isomers (ortho-xylene, meta-xylene, and para-xylene), ethylbenzene and some impurities (example: trimethylbenzene, phenol, thiophene, pyridine, toluene, pseudocumene, benzene, nonaromatic hydrocarbons). M-xylene is always the most abundant isomer. The proportion of the different components depends on the origin of the xylene. For example, xylene from petroleum via the catalytic reforming process has the following typical composition: 25% ortho-xylene, 40% meta-xylene, 20% para-xylene, and 15% ethylbenzene; xylene from petroleum via cracked gasoline has the following typical composition: 17% ortho-xylene, 23% para-xylene, 37% meta-xylene, and 23% ethylbenzene." (free translation)
It therefore appears that with commercial xylene, frequently presented as CAS number 1330-20-7 (mixture of isomers), ethylbenzene is always present in a non-negligible proportion. As a result, it is strongly recommended that ethylbenzene be analyzed when the presence of xylenes is suspected.
New guide is now on line
In the context of an IRSST research project, the Guide for the safe use of isocyanates has been updated and the new version is now available on the IRSST's Web site. The Guide de prévention pour une utilisation sécuritaire des isocyanates – Démarche d’hygiène du travail (Prevention Guide for Safe Use of Isocyanates – Industrial Hygiene Approach, an English version will be available at the end of May 2013) is intended for Québec employers and workers as well as for different occupational health and safety practitioners. Users of the IRSST's laboratory services will benefit from it, mainly due to the concepts of anticipation, identification and evaluation of isocyanate exposure presented in the Guide.
A new inhalable metals particulate analysis service is available in the IRSST laboratories. The metals that can be determined are the same as those sampled as total dust, meaning on closed cassette (25 or 37 mm), and analyzed using IRSST method 362, or IRSST method 359 for beryllium. The inhalable fraction of airborne dusts is described in section 2.3 Aerosolsof the IRSST's Sampling guide for air contaminants in the workplace (available in French only, but will be in English in the near future). Sampling is done with an IOM (Institute of Occupational Medicine) sampler and the metals are determined by ICP-MS (Inductively Coupled Plasma Mass Spectrometry).