If employees are performing silica-generating tasks on a particular floor of a construction site, does the employer need to restrict access such that no other employees can enter the floor where the silica-generating tasks are occurring?

No. OSHA does not intend for the standard to prohibit all employees from entering entire areas of a construction site simply because employees in those areas are performing some work involving the generation of silica. The standard requires employers to restrict access to work areas only in certain situations, e.g., “where respirator use is required under Table 1 or an exposure assessment reveals that exposures are in excess of the PEL.” 81 Fed. Reg. at 16803. Furthermore, the competent person, who is designated by the employer to implement the written exposure control plan under paragraph (g)(4) of the standard, could identify additional situations where limiting access is necessary. See 81 Fed. Reg. at 16803. Also, the rule calls only forminimizing the number of employees in the relevant work areas. The standard does not preclude employees from entering work areas where silica-generating tasks are occurring when it is necessary for them to do so. However, the employer must comply with the standard (including Table 1 or alternative exposure control methods) as it applies to any employees entering these areas.