Tool
From emission rate to room concentration
Estimates the steady-state concentration a product produces in a room from its area-specific emission rate, the area installed, the room volume and the air exchange rate.
- Sources Laminate flooringWood-based panels (particleboard, MDF, plywood)Emission
- Factors Formaldehyde (CH₂O)Volatile organic compounds (VOCs)BenzeneToluene (C₇H₈)
- Interventions VentilationAir exchange rate (air changes per hour)Source control
Standards & bodies: ISO 16000 seriesMethods: Exposure assessment
Formula
c(µg/m³) ≈ (SER(µg/(m²·h)) × A(m²)) ÷ (V(m³) × n(h⁻¹))
The step nobody publishes
Product sheets speak in emission rates per square metre and per hour; guidelines speak in micrograms per cubic metre of air. Between the two sits a room. The bridge is a mass balance: at steady state, what the product releases each hour equals what the ventilation carries away each hour, and the concentration settles at the value where those match.
That is the whole model. Its usefulness is that it is explicit — every assumption behind the number is on this page, and each one is a way the estimate can be wrong.
A worked example
A new laminate floor covering 20 m² emits formaldehyde at 60 µg/(m²·h) in a 42 m³ bedroom with the windows shut at 0.5 h⁻¹ air exchange. The estimate is about 57 µg/m³ — below the WHO short-term guideline of 0.1 mg/m³, and above the range a bedroom without a fresh source would normally sit in. Double the ventilation and it halves; let the floor age and the emission rate falls with it.
Measured emission rates for this product class run far apart: the study of laminate flooring in CKB 0258 reports rates that differ by more than an order of magnitude between products, which is why a rate from a sheet for the product you actually bought is worth more than a typical value.
Comparing the result with a limit
Convert the units before comparing. Emission sheets are in µg/m³ or mg/m³, some guidelines are in ppb, and the unit converter does that step. The limits themselves are in the indoor air quality limits table with the jurisdiction and the averaging time each belongs to — a 30-minute guideline and an annual limit are not comparable numbers, and a steady-state estimate corresponds to neither exactly.
Assumptions
- Steady state: emission and removal have balanced out. At an air exchange rate of 0.5 h⁻¹ that takes about six hours; before then the concentration is lower.
- Perfect mixing: the room is one well-stirred volume, with no gradient between the floor and the ceiling and no still corner.
- Constant emission: the rate is the one on the sheet and does not fall over the days and weeks after installation, which in reality it does.
- No other source of the same substance in the room, and none coming in with the outdoor air.
- No sink: nothing is adsorbed on surfaces, taken up by furnishings or removed by a filter or by chemistry.
Outside these assumptions the number is still arithmetic, but it stops describing the room.
What this tool does not do
- It is an estimate, not a measurement. It answers what a product would do in a room under these assumptions; only a measurement says what your room is doing.
- It runs one direction only — from emission to concentration. Working back from a measured concentration to a product's emission rate is not valid, because the measurement contains every other source in the room as well.
- Real emission decays. Formaldehyde from a new laminate floor falls over weeks to months and rises again with temperature and humidity, so a single rate describes one moment of that curve.
- It says nothing about exposure. Concentration is not dose; how long a person is in the room and how they breathe decides that.
- It cannot compare the result with a limit for you — the units on the sheet and in the limit are often different, so convert first.
Frequently asked questions
Where do I find the emission rate for a product?
On the technical data sheet or the emission certificate, usually as an area-specific emission rate in µg/(m²·h) measured in a test chamber to EN 16516 or ISO 16000-9, at 23 °C and 50 % relative humidity after 28 days. Emission-class labels quote a chamber concentration instead; that is a different quantity and cannot be used here.
What air exchange rate should I assume?
For a dwelling with the windows shut, 0.2–0.5 h⁻¹ covers most rooms; a well-ventilated room reaches about 1 h⁻¹ and an open window several times that. If a mechanical system states an airflow, divide it by the room volume to get the rate.
The result is above the limit. Does that mean the product is unsafe?
It means the assumption set produces a concentration above the limit, most often because the air exchange rate entered is low and the emission rate is the fresh one. Ventilate, wait, and then measure. The calculation is a reason to check, never a finding about your room.
Sources
- Offermann Formaldehyde Emission Rates From Lumber Liquidators Laminate Flooring Manufactured in China (2016). CKB 0258
- Naldzhiev Method development for measuring volatile organic compound (VOC) emission rates from spray foam insulation (SPF) and their interrelationship with indoor air quality (IAQ), human he... (2017). CKB 0148
- Estimation of infiltration and ventilation rates in an office room with 145mm-diameter… (2023). doi:10.20944/preprints202304.0499.v1 CKB 0348
- Data Table D-0001: Indoor air quality limits by jurisdiction (v1.0)
- EN 16516: Construction products — Assessment of release of dangerous substances — Determination of emissions into indoor air.
- ISO 16000-9: Indoor air — Determination of the emission of volatile organic compounds from building products and furnishing — Emission test chamber method.
CKB = document number in the Coridum Knowledge Base, our curated library of peer-reviewed studies. Follow the DOI for the original paper.
Cite this page
Coridum Research. From emission rate to room concentration. Coridum Knowledge T-0002, 6 September 2026. https://coridum.com/k/T-0002/