A concentration limit only means something once the document that sets it also says where the measurement is taken, how many points are measured and over what period. Dubai Municipality's Technical Guidelines for Indoor Air Quality for Healthy Life, reference DM-HSD-GU119-IAQ, Version 4, issued 11 December 2024, does all three. Table 5 fixes how many sampling points a floor area attracts, clause 9-8-7 fixes the geometry of probe placement and the distances that must be kept from walls, floors, doors, lifts and entrances, and the same clause fixes the measurement basis at 8 hours with a defined surrogate where continuous measurement over that period is impracticable. Those provisions are the difference between a survey that can be assessed against Table 1 or Table 2 and a set of readings that cannot. This page sets out the protocol the guideline prescribes.
Table 5 of the guideline sets sampling point numbers by floor area. For areas under 3,000 m2 the requirement is 1 sampling point per 500 m2. From 3,000 m2 to under 5,000 m2 the requirement is 8 points. From 5,000 m2 to under 10,000 m2 it is 12 points. From 10,000 m2 to under 15,000 m2 it is 15 points. From 15,000 m2 to under 20,000 m2 it is 18 points. From 20,000 m2 to under 30,000 m2 it is 21 points. Above 30,000 m2 the requirement returns to a density, at 1 sampling point per 1,200 m2.
The structure of the table is worth reading carefully. It begins as a density, becomes a fixed count across a series of bands, and then reverts to a coarser density for the largest buildings. The number of points is therefore not a linear function of area, and a building sitting near a band boundary can attract a materially different count from one marginally smaller or larger.
Because the count is set by floor area rather than by room count, the distribution of points across a building is a design decision constrained by the placement rules in clause 9-8-7 rather than a free choice. The count answers how many; the clause answers where.
Clause 9-8-7 sets the geometry of the measurement. The probe is placed 150 to 200 cm from walls and 100 to 200 cm from the floor, which locates the sample in the occupied volume of the space rather than against a surface where local effects dominate.
The clause also imposes separation from openings and circulation features. In a corridor or lobby, a sampling point is not placed within 3.5 m of a lift or an entrance, and measurements are taken 3 m from doors. Those distances keep the sample away from the transient air movement associated with door and lift operation, which would otherwise make a reading a record of the opening rather than of the space.
Placement and count operate together. A building may satisfy the Table 5 count and still produce an unusable survey if the points sit in positions the clause excludes, and conversely a correctly placed set of points that is short of the Table 5 count does not cover the building the guideline expects to be covered.
Clause 9-8-7 provides that measurements are taken on an 8-hour basis except where otherwise specified. That basis matches the averaging periods carried by the tables: Table 1 expresses TVOC at 300 micrograms per cubic metre over 8 hours and formaldehyde at 0.01 ppm over 8 hours, and Table 2 expresses TVOC at 0.6 mg/m3, carbon dioxide at 800 ppm, carbon monoxide at 9 ppm and ozone at 0.06 ppm, each over 8 hours.
The exception in the phrase except where otherwise specified is doing real work. The guideline's formaldehyde entry includes a short-term value of 0.08 ppm, equal to 0.1 mg/m3, over 30 minutes, which is measured on its own basis and cannot be derived from an eight-hour figure. A survey that reports only eight-hour formaldehyde has not answered the thirty-minute entry.
Because the same numeral appears in more than one instrument on more than one basis, the reporting of the basis is as important as the reporting of the value. The same number appears under both instruments on different bases. Dubai Municipality's eight-hour formaldehyde value is 0.01 ppm, and its 0.08 ppm figure is a thirty-minute short-term value. Al Sa'fat separately and correctly applies 0.08 ppm as an eight-hour time-weighted average. It is therefore incorrect to attribute 0.08 ppm over eight hours to Dubai Municipality.
The guideline anticipates that continuous measurement across a full eight hours will not always be practicable. Where that is the case, clause 9-8-7 permits the average of half-hour measurements taken at four time-slots evenly distributed over business hours.
The surrogate is defined tightly. It is four time-slots rather than an unspecified number of visits, the slots are evenly distributed rather than clustered, the distribution is across business hours rather than across the calendar day, and each slot is a half-hour measurement rather than a spot reading. A survey that departs from any of those elements is not the method the clause describes.
The surrogate produces an average intended to stand in for the eight-hour value, so the resulting figure is still assessed against the eight-hour entries in the tables. It does not create a separate, more lenient basis, and it does not answer the thirty-minute short-term formaldehyde entry.
The guideline prescribes count, placement, basis and surrogate. Analytical technique, instrument selection, calibration practice and detection limits are the subject of separate technical references and are not addressed here.
The protocol also does not answer scope. Whether a building is reached by clause 9-8-3 as a new building entering the voluntary certification route, or by clause 9-8-4 as an existing building for which testing must be carried out, is determined before any sampling plan is drawn, as is whether the premises fall inside the exclusion of premises exclusively dedicated to industrial and medical sectors, for example hospitals and factories.
Finally, the protocol does not substitute for accreditation. Testing must be by a company or laboratory accredited by EIAC, the Emirates International Accreditation Centre, and a survey carried out to the letter of Table 5 and clause 9-8-7 by a body outside that condition does not support a compliance position under the guideline.
Al Sa'fat, the Dubai Green Building System, 2nd edition January 2023, sets its own testing expectations at clause 401.07 for listed categories of existing building, expressing formaldehyde, TVOC, carbon dioxide, carbon monoxide, ozone and respirable dust as 8-hour time-weighted averages and bacteria and fungi each below 500 CFU per cubic metre as per-sample counts that are not time-weighted.
The two per-sample microbiological counts sit outside the time-weighted logic entirely, which is a further reason a survey report must state the basis for every parameter rather than applying a single heading to the whole exercise.
Where a building is reached by both documents, a sampling plan that satisfies the Table 5 count and the clause 9-8-7 geometry provides the structure for the Dubai Municipality assessment, while the Al Sa'fat parameters and bases are read against the same survey only where the survey was designed to produce them.
1 point per 500 m2 under 3,000 m2; fixed counts of 8, 12, 15, 18 and 21 across the bands; 1 point per 1,200 m2 above 30,000 m2.
150 to 200 cm from walls and 100 to 200 cm from the floor under clause 9-8-7.
Not within 3.5 m of a lift or entrance in a corridor or lobby, and 3 m from doors.
Average of half-hour measurements at four time-slots evenly distributed over business hours.
The sampling provisions described here come from Dubai Municipality's Technical Guidelines for Indoor Air Quality for Healthy Life, reference DM-HSD-GU119-IAQ, Version 4, issued 11 December 2024. Clause 9-8-3 operates a voluntary certification route for new buildings and clause 9-8-4 states that indoor air testing must be carried out for existing buildings, so the protocol serves both a voluntary and a required application depending on the building.
Testing must be by a company or laboratory accredited by EIAC, the Emirates International Accreditation Centre.
Table 5 of the Dubai Municipality guideline sets 1 point per 500 m2 for areas under 3,000 m2, 8 points from 3,000 to under 5,000 m2, 12 points from 5,000 to under 10,000 m2, 15 points from 10,000 to under 15,000 m2, 18 points from 15,000 to under 20,000 m2, 21 points from 20,000 to under 30,000 m2, and 1 point per 1,200 m2 above 30,000 m2.
Clause 9-8-7 places the probe 150 to 200 cm from walls and 100 to 200 cm from the floor. In a corridor or lobby a point is not within 3.5 m of a lift or an entrance, and measurements are taken 3 m from doors. Those separations keep the sample out of the transient air movement associated with doors and lift operation.
Clause 9-8-7 provides that measurements are on an 8-hour basis except where otherwise specified, and that where continuous measurement over eight hours is impracticable the average of half-hour measurements at four time-slots evenly distributed over business hours may be used. The resulting average is still assessed against the eight-hour entries in the tables.
The guideline addresses how many points, where the probe sits and over what period the measurement runs. Analytical technique, instrument selection and calibration are technical matters covered by separate references. The guideline instead conditions validity on accreditation, requiring that testing be by a company or laboratory accredited by EIAC, the Emirates International Accreditation Centre.