Inhalation regulatory requirements

Rutschmann and Buser 1991 Wright 1987). Air is the medium of most concern for human exposure to this chemical. Exposure may also occur from water, especially in the vicinity of hazardous waste sites or industrial sources. The existing analytical methods can provide determinations for these chemicals at levels sufficiently low to meet regulatory requirements (NIOSH 1977a, 1977b, 1984). Assuming that an adequate quantity of air is passed through the collector (for example a volume of at least 41 m is required to detect a level equivalent to the intermediate inhalation MRL of 2x 10 " ppm for... 

Most regulatory jurisdictions will consider a science-based rationale to waive an occupational or residential exposure data requirement. For example, under NAFTA, the USEPA and Health Canada s PMRA have agreed upon guidance for considering a waiver for inhalation exposure data. Considerations are based on volatility, engineering considerations and particle size, and are outlined in Table 10.1. 

The discussion above indicates that little or no extra preclinical studies are required for well known excipients. From an unofficial FDA regulatory perspective, this view is supported for inhalation excipients by De George et who state that no additional toxi-... 

Materials to be tested for acute toxicity can be administered to the animals by one or more of a number of routes. These routes correspond to the various ways exposures can occur in humans. The regulatory agencies frequently require standard packages of acute studies which include the routes listed below. In any case, the routes selected should be related to a possible human exposure. It would be useless, for example, to test a viscous grease with a low vapor pressure for inhalation toxicity, as this would not be a possible route of exposure. 

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