Safety and Health Topics | Respirable Crystalline Silica ...
Jun 23, 2020· The standard does not include a specific exemption for tasks with only shortterm exposures (, tasks with exposure for 15 minutes a day or less).However, the standard does not apply where the employer has objective data demonstrating that employee exposure to respirable crystalline silica will remain below 25 μg/m 3 as an 8hour TWA under any foreseeable conditions.