Option 2, the "performance option" applies when employees are not using engineering controls listed in Table 1. Examples of engineering controls not listed in Table 1 include using miter saws or panel saws to cut the fiber cement, or using fans to disperse fiber cement dust.
Under the performance option, employers may rely on any combination of objective data
and air monitoring data to show that employee exposure is below the PEL.
The combination of objective data or air monitoring data must reflect workplace conditions that closely resemble the employer's operation on their jobsite, or represent a "worst case" production of silica dust.
James Hardie has compiled a list of reports that may be used as objective data to support your written exposure plan.