The WELL Building Standard, a certification mark of the International WELL Building Institute, sets air-quality precondition thresholds that are checked through the accepted performance-verification routes. The figures on this page are drawn from the standard text that International WELL Building Institute pbc publishes openly online. They are expressed primarily as mass concentrations, with the parts-per-million and parts-per-billion values stated here only where the scheme owner provides its own conversion.
The thresholds belong to the current v2 Air quality precondition and must be read with its applicability notes and alternatives. A bare figure can be misleading where the standard provides a conditional pathway for a space type or outdoor-air context.
Mass concentration is the primary expression used on this page. Micrograms per cubic metre and milligrams per cubic metre state the mass of the measured substance within a volume of air. For selected gases, the scheme owner also expresses the same threshold as parts per million or parts per billion.
The parallel expressions are not independently chosen limits. The parts-per-million and parts-per-billion figures are the owner's conversions, and reporting should preserve the stated pairing.
The thresholds are scheme requirements, not a general statement that every building with a result below them is free from all air-quality concerns. They also do not replace UAE legal duties, authority requirements, project specifications or a separate technical investigation undertaken for another purpose.
For fine particulate matter, the published precondition threshold is 15 micrograms per cubic metre or lower. This figure must never be presented as a universal limit for every space and every project location.
The standard carries conditional alternatives for spaces such as commercial kitchens and industrial areas. It also carries an alternative pathway for projects located where annual outdoor fine-particulate concentrations are high. Those qualifications are part of the requirement, not optional explanatory detail.
The outdoor-air qualification is particularly important in the Gulf, where regional background conditions can affect indoor concentrations. A UAE project must determine the applicable pathway from the current standard text rather than assume that 15 micrograms per cubic metre governs every circumstance.
The caveat does not mean that the ordinary figure can be ignored whenever outdoor air is dusty or a building contains a kitchen. The project must satisfy the conditions of the relevant alternative and provide the evidence required by the scheme. A general statement about local climate or building use is not itself a substitute for the applicable pathway.
For coarse particulate matter, the published threshold is 50 micrograms per cubic metre or lower. As with fine particulate matter, the result must be interpreted within the space classification and applicability provisions of the current precondition.
Commercial kitchens and industrial areas can be subject to conditional alternatives rather than the ordinary pathway applied to other occupiable spaces. The existence of an alternative should be confirmed from the scheme text for the actual project scope; it should not be assumed merely because a space contains equipment, food preparation or industrial activity.
The coarse- and fine-particle figures are separate requirements. Achieving one does not demonstrate the other, and the evidence should keep the parameters distinct.
This page does not explain particle formation, health effects, toxicology or sampling technique. Its purpose is limited to stating the scheme threshold and making clear that the ordinary particulate figures have applicability qualifications.
For carbon monoxide, the standard text sets a threshold of 10 milligrams per cubic metre. The scheme owner also expresses this as 9 parts per million. The mass concentration is the primary expression, and the parts-per-million value is the owner's accompanying conversion.
For ozone, the published threshold is 100 micrograms per cubic metre. The scheme owner expresses the same limit as 51 parts per billion. The two forms should be reported as a paired statement rather than treated as separate criteria.
A project report should retain the submitted result's unit and make its relationship to the threshold clear. Any conversion should follow the accepted performance-verification requirements.
Neither threshold should be expanded into commentary on pollutant sources, reactions or health effects on this page. Those topics belong to separate independent air-quality resources and are not part of this certification-reference explanation.
For formaldehyde, the current published precondition threshold is 10 micrograms per cubic metre. International WELL Building Institute pbc describes this as approximately 8 parts per billion.
The mass concentration should remain the primary stated value because that is the form in which the current threshold is set. The approximate parts-per-billion figure is the scheme owner's conversion and should be identified as such where it is included.
Older values from superseded material continue to circulate in secondary summaries. They should not be inserted into a v2 project brief, testing schedule or compliance statement without checking the current standard text. The current figure stated above is the one relevant to this page.
Formaldehyde also remains separate from the total volatile organic compound measure. A result for the broader total does not erase or replace a distinct formaldehyde requirement where that parameter is required by the applicable feature pathway.
For total volatile organic compounds, the published threshold is 500 micrograms per cubic metre. The result is expressed as a mass concentration and no parts-per-million or parts-per-billion conversion is stated here.
The total figure is an aggregate measure and must not replace separate requirements for specified individual compounds. The current feature text may require evidence for both.
This distinction matters in scope preparation. A schedule that requests only a total volatile organic compound result may be incomplete where the selected compliance route also requires individual-compound results. The project team and Performance Testing Agent should align the evidence package with the current feature rather than infer that one aggregate number resolves every volatile-compound requirement.
The page does not reproduce the individual-compound list or associated limits. Reproducing the scheme's feature table would conflict with the purpose of an independent explanatory summary, and the current standard text remains the source for the complete project requirement.
A measured concentration does not become a certification decision merely because it appears below a figure stated on this page. The result must come from an accepted verification route, be linked to the required location and project conditions, and be submitted with the supporting evidence required by the scheme.
The WELL Performance Testing Agent compiles the performance evidence through the approved provider structure. A separate WELL Reviewer then assesses those results together with the relevant project documentation and determines whether the feature is achieved. The distinction between testing and review is explained fully on the neighbouring performance-verification page.
Results should also be reported with their units, parameter names and applicable pathway intact. Removing the particulate caveat, changing the expression of a gas threshold or treating the total volatile organic compound result as a replacement for individual compounds can alter the meaning of the requirement.
The scheme owner's current materials identify the Air quality precondition as one of the features that may be verified through performance testing or accepted sensor-data routes, depending on the applicable part and pathway. The current feature text should therefore be checked when defining the final verification package.
Certification under the scheme is voluntary and is not required by any authority in the United Arab Emirates. The thresholds on this page are scheme criteria and should not be relabelled as UAE statutory indoor-air limits.
The Gulf context is most important when applying the fine-particulate requirement. High annual outdoor fine-particulate conditions can engage the conditional alternative in the standard, but the project must establish applicability through the scheme's stated conditions rather than through a general regional assumption.
This website is an independent information resource with no affiliation, endorsement, accreditation, partnership, assessor, provider or agency status under the scheme. It does not conduct performance testing, review results, award certification or act for International WELL Building Institute pbc.
The neighbouring pages explain the Health-Safety Rating, the Performance Rating, the two-stage verification structure and the map of quantities measured on site without repeating those subjects here.
An independent resource. WELL is a certification mark of the International WELL Building Institute pbc. No affiliation, endorsement or accreditation.
The ordinary published threshold is 15 micrograms per cubic metre or lower. It is not universal: conditional alternatives apply to spaces such as commercial kitchens and industrial areas and to projects in locations with high annual outdoor fine-particulate concentrations, a qualification of particular importance in the Gulf.
The published threshold is 50 micrograms per cubic metre or lower. Applicability and any conditional space-type pathway must be checked against the current standard text.
Carbon monoxide is limited to 10 milligrams per cubic metre, which the scheme owner also expresses as 9 parts per million. Ozone is limited to 100 micrograms per cubic metre, expressed by the owner as 51 parts per billion.
The current threshold is 10 micrograms per cubic metre, approximately 8 parts per billion using the scheme owner's conversion. Superseded figures found in older summaries should not be used for a current v2 project.
The threshold is 500 micrograms per cubic metre. That total does not substitute for separate requirements applying to specified individual compounds.
No. They are thresholds within a voluntary certification scheme. UAE law, authority requirements and project-specific standards must be identified and applied independently.
This site is an independent information resource. It is not affiliated with, endorsed by, accredited by or authorised by the International WELL Building Institute pbc, which owns the WELL certification mark, and it is not a certification body, an assessor, a performance testing provider or a scheme partner. Nothing on this page can certify, assess or award anything under the scheme, and nothing here is a substitute for the scheme's own published documentation. Requirements are summarised factually rather than reproduced; where a numeric threshold is stated it is drawn from documentation the scheme's owner publishes openly, and the specific figure is cited rather than the table it sits in. Certification under the scheme is voluntary and is not required by any authority in the United Arab Emirates.