Formaldehyde in Indoor Air
Formaldehyde is the simplest aldehyde with a molar mass of 30.03 g/mole and a boiling point of -19oC. It is a flammable, colourless, reactive gas with a strong, pungent odour. It is soluble in water and reacts relatively quickly with other pollutants in the air.
How is Formaldehyde Formed
Formaldehyde is present in ambient air through oxidation of hydrocarbons with a natural background mean concentration of 0.5 ug/m3. One major source of formation is through combustion process such as vehicle exhaust, wood burning, heating, smoking, gas appliance use and industrial emission. In urban outdoor environments, the levels of formaldehyde can be much higher depending on the traffics and local conditions. The concentrations of formaldehyde is much higher in indoor air than outdoor air because indoor environments usually contain many sources of formaldehyde.
Other Indoor Sources of Formaldehyde
Formaldehyde can cause irritation of the skin, eyes, nose, and throat as well as increased risk of asthma . It is a skin irritant by direct skin contact with formaldehyde solutions in concentrations higher than 2%, which can cause allergic contact dermatitis. People with eye, skin, respiratory, or allergic conditions, and those with asthma, are potentially more susceptible to the irritant effects of formaldehyde. Children and the elderly may be more sensitive as well. High levels of exposure may cause some types of cancers. Formaldehyde is a known human carcinogen based on sufficient human and animal inhalation studies.
Health Effects of Formaldehyde
Formaldehyde can cause irritation of the skin, eyes, nose, and throat as well as increased risk of asthma . It is a skin irritant by direct skin contact with formaldehyde solutions in concentrations higher than 2%, which can cause allergic contact dermatitis. People with eye, skin, respiratory, or allergic conditions, and those with asthma, are potentially more susceptible to the irritant effects of formaldehyde. Children and the elderly may be more sensitive as well. High levels of exposure may cause some types of cancers. Formaldehyde is a known human carcinogen based on sufficient human and animal inhalation studies.
What are the Guidelines for Formaldehyde
I)
1. Residential Air quality Guideline for formaldehyde – Health Canada
| Exposure Period | Concentration | Critical Effect | |
| ug/m³ | ppb | ||
| 1 Hour | 123 | 100 | Eye Irritation |
| 8 Hours | 50 | 40 | Respiratory Symptoms in Children |
2. WHO Guidelines for Indoor Air Quality: Selected Pollutants
Formaldehyde: 100 ug/m3 (30-minute average concentration)
3. Occupational Health Exposure Limits (ACGIH)
Formaldehyde (TWA): 0.1 ppm (100 ppb); STEL: 0.3 ppm (300 ppb)
4. Occupational Health Exposure Limits (Ontario Ministry of Labour)
Formaldehyde (TWA): NA; STEL: 1 ppm or Ceiling: 1.5 ppm
5. Occupational Health Exposure Limits (OSHA)
Formaldehyde (PEL): 0.75 ppm; STEL: 2 ppm
II)
1. USEPA Formaldehyde Standards for Composite Wood Products Act
The formaldehyde emissions standards vary by type of regu Formaldehyde can cause irritation of the skin, eyes, nose, and throat as well as increased risk of asthma . It is a skin irritant by direct skin contact with formaldehyde solutions in concentrations higher than 2%, which can cause allergic contact dermatitis. People with eye, skin, respiratory, or allergic conditions, and those with asthma, are potentially more susceptible to the irritant effects of formaldehyde. Children and the elderly may be more sensitive as well. High levels of exposure may cause some types of cancers. Formaldehyde is a known human carcinogen based on sufficient human and animal inhalation studies.
lated product. In the table below, the product is aligned with its emissions standard in parts per million (ppm).
| Product | Emission Standard |
|---|---|
| Hardwood Plywood – Veneer Core | 0.05 ppm of formaldehyde |
| Hardwood Plywood – Composite Core | 0.05 ppm of formaldehyde |
| Medium-Density Fiberboard | 0.11 ppm of formaldehyde |
| Thin Medium-Density Fiberboard | 0.13 ppm of formaldehyde |
| Particleboard | 0.09 ppm of formaldehyde |
2. California Air Resources Board (CARB) Composite Wood
Both regulations for CARB and EPA have similar emission standards as listed above. However, there are a few differences. Unlike the California requirements, among other things, the EPA rule:
- Requires records be kept for 3 years versus 2 years;
- Requires importers to provide import certification under TSCA beginning March 22, 2019;
- Requires manufacturers to disclose upon request formaldehyde testing results to their direct purchasers; and
- Requires laminated products not exempted from the definition of hardwood plywood to meet the hardwood plywood formaldehyde emissions standard beginning March 22, 2024.
3. Canada CSA Standard 160 Formaldehyde Emission Standard for Composite Wood Panel
| Hardwood Plywood | Particleboard | Medium-Density Fiberboard | hin Medium-Density Fiberboard | |
|---|---|---|---|---|
| CMAX (PPM) | 0.05 | 0.09 | 0.11 | 0.13 |
CASSEN Experience in Formaldehyde Analysis
1) National Studies of Fromaldehyde, Acrolein and Acetaldehyde
CASSEN Testing Laboratory has conducted the analysis of formaldehyde , acrolein and acetaldehyde for samples collected nationally for Health Canada since 2001after the laboratory developed a method to analyse acrolein at ultra- low concentrations accurately. The data obtained in early years was used in the implementation of Health Canada’s “Residential Air quality guideline for formaldehyde” and a few papers were published in collaboration with Health Canada subsequently:
- “Levels and determinants of formaldehyde, acetaldehyde, and Acrolein in residential indoor air in Prince Edward Island, Canada”, Environmental Research, September, 2004
- “Air Change Rate and Concentrations of Formaldehyde in Residential Indoor Air”, Atmospheric Environment, Volume 42, Issue 10, March 2008,
- “Housing characteristics and indoor concentrations of nitrogen dioxide and formaldehyde in Quebec City, Canada”, Environmental Research, Volume 102, September 2006
2) RetroFoam Insulation
In 2008, Health Canada issued a “cease and desist” order to prohibit importation and sale of RetroFoam, which illegally contained formaldehyde and was installed in numerous homes in Canada. CASSEN coordinated consecutive seasonal air quality testing of formaldehyde on behalf of Health Canada for thousands of homeowners where RetroFoam had been installed. In the project, CASSEN was involved with both administration of the air quality testing and the analysis of formaldehyde.
3) Acrolein Study
Acrolein is an alpha-beta unsaturated aldehyde and is a reactive and unstable compound. It is a clear, colourless liquid with an intensively acrid odour and is highly irritating to mucous membranes, especially the upper respiratory tract and eyes and can cause even death upon high level exposure. Acrolein is highly flammable, easily polymerized and can react with other compounds. It is classified under Priority Substance List and Toxic Substance List. Their presence in indoor air is quite low. Because of its reactivity, CASSEN has investigated different methods for its reliable and accurate determination at low levels. In 2017, under Health Canada contract, CASSEN conducted a feasibility study for the determination of acrolein in air using passive adsorption/thermal desorption gas chromatography/mass spectrometry. The study explored different methods for the detection of acrolein at low levels reminiscent of their concentration in indoor air.