This is a legacy version of the WELL Building Standard. Please check the latest version here.

Air quality standards

Air quality standards

Intent: 

To ensure a basic level of high indoor air quality.

BACKGROUND

Pollutants generated indoors can lead to a variety of symptoms and health conditions. Volatile organic compounds (VOCs), combustion byproducts and airborne particulate matter are known to trigger nausea, headaches, asthma, respiratory irritation and allergies. While ambient outdoor air is often better quality, natural ventilation methods, operable doors and windows, and general building envelope infiltration can diminish indoor air quality if external air quality parameters are poor.

Part 1
Standards for Volatile Substances

The following conditions are met:
a.1
Formaldehyde levels less than 27 ppb.
b.1
Total volatile organic compounds less than 500 μg/m³.

Part 2
Standards for Particulate Matter and Inorganic Gases

The following conditions are met:
a.2
Carbon monoxide less than 9 ppm.
b.2
PM₂.₅ less than 15 μg/m³.
c.3
PM₁₀ less than 50 μg/m³.
d.3
Ozone less than 51 ppb.

Part 3
Radon

The following conditions are met in projects with regularly occupied spaces at or below grade:
a.4
Radon less than 0.148 Bq/L [4 pCi/L] in the lowest occupied level of the project.

Part 4
Operational Kitchen Air Quality

The following air quality concentrations are met in the commercial kitchen space:
a.2
Carbon monoxide levels less than 35 ppm.
b.2
PM₂.₅ less than 35 μg/m³.
c.2
Nitrogen dioxide less than 100 ppb.
d.129
Formaldehyde less than 81 ppb.