Q testing here will be carried out over three days, in order to:• Determine if there is a challenge to the filter from the environment• Determine if there is a challenge due to contamination in the distribution pipework• Acceptance criteria: air after the pre-filter≤ 0.1 mg/m3• Air from the POU ≤ 0.1 mg/m3Note: The expected result is that “the hydrocarbon level should not exceed that measured post the intermediate