Comprehensive Residential IAQ Kit

Four passive badges, four different collection chemistries — solvents, formaldehyde, ammonia and nitrogen dioxide — deployed together in one room so the four results can be read against each other.

Nitrogen dioxide is the addition that makes this tier interesting: it's the marker of combustion indoors — gas cooktops, unvented heaters, attached garages — and the one parameter here that points at a specific and very common household source. Every parameter is reported as a named, quantified concentration rather than folded into a score.

Use the guide to choose the room — for this kit, a room adjacent to a gas appliance or an attached garage is often the most informative choice. Open all four badge pouches and write down the exact start time. Place all four together (a few inches apart, same surface) at breathing height (3–5 ft), in the middle of the room, away from vents, windows, purifiers and direct sun.

Leave them undisturbed for 8 to 12 hours — cook, clean and ventilate as you normally would. Seal all four back into their pouches, record the end time, and post them together the same day. Return within 14 days of use.

Each badge uses the collection chemistry matched to its analyte: charcoal + GC-MS for the 25 solvents; DNPH + HPLC for formaldehyde and other carbonyls; a treated medium + ion chromatography for ammonia; and a dedicated collection chemistry for nitrogen dioxide. All four deploy together in the same room over the same period.

Because each badge's uptake rate is characterised, every parameter converts into a time-weighted average concentration for the period recorded — combined into one four-parameter report that reads as a coherent picture of one space rather than four unrelated measurements.