Ventilation: Approved Document F, Volume 2 — Buildings other than dwellings

B O N L I N E V E R S I O N Table B1 Indoor air pollutants guidance values(1)(2) Pollutant Exposure limit Exposure time Guidance Carbon monoxide (CO) 100mg/m3 15-minute average WHO, 2010 30mg/m3 1-hour average WHO, 2010 35mg/m3 8-hour average HSE, 2020 (occupational exposure) Nitrogen dioxide (NO ) 200μg/m3 1-hour average WHO, 2010 2 40μg/m3 1-year average WHO, 2010 Formaldehyde (CH O) 100μg/m3 30-minute average WHO, 2010 2 10μg/m3 1-year average PHE, 2019 TVOC(3) 300μg/m3 8-hour average ECA, 1992/WHO, 2010 Ozone 100μg/m3 DETR, 1994 NOTES: 1. No safe levels can be recommended for benzene or trichloroethylene so they have not been considered in the definition of ventilation rates in buildings. The best strategy for reducing their concentration indoors may be to control them at source. 2. Even if the designer and builder choose to reduce volatile organic compound (VOC) levels in buildings by controlling them at source, the ventilation requirements must still be met. 3. The total volatile organic compound (TVOC) metric is representative of all airborne indoor air VOC concentrations and should not be used as a direct indicator of health. The simplified metric is used as an indicator for the purposes of ventilation control strategies. As an alternative to the TVOC limit, individual VOC limits may be used where justified in accordance with the guidance in paragraph B3. B3 As an alternative to using TVOC, the individual VOCs may be applied where their use is supported by robust independent evidence. Public Health England’s Indoor Air Quality Guidelines for Selected Volatile Organic Compounds (VOCs) in the UK should be used. Testing against these metrics is likely to be more complex than testing against TVOC. Where the Health and Safety Executive gives guidance for specific situations, that guidance should be followed in preference to the guidance given here. 28 Approved Document F Volume 2, 2021 edition Building Regulations 2010 O N L I N E V E R S I O N