Publication 725 2016 Revision 020216

031012013

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AN UPDATE ON

FORMALDEHYDE

The U.S. Consumer Product Safety Commission (CPSC) has produced this booklet to tell you 

about formaldehyde and its potential impact on indoor air quality.

This booklet describes what formaldehyde is, what products it may be found in, where you may 

come in contact with it, how exposure to formaldehyde may affect your health, and how you 

might reduce your exposure to it.
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What is Formaldehyde?

Formaldehyde is a colorless, reactive, strong-smelling gas at room temperature. It is one 

chemical in a large family of chemical compounds called volatile organic compounds (VOCs). 

The term volatile means that the compounds vaporize or become a gas at room temperature. 

Formaldehyde can be manufactured as a liquid (formalin) or a solid (paraformaldehyde). 

Formaldehyde is an important industrial chemical used to make other chemicals and different 

types of products, such as: home furnishings, household cleaners, paints, textiles, landscape and 

yard products, medicinal and personal care products, and pesticides. Chemicals that are created 

with formaldehyde or have formaldehyde added to them include the following:

• resins and lubricants

• polyoxymethylene plastics

• 1,4-butanediol

• methylene diphenyl diisocyanate

Formaldehyde can be released into the air (off-gas) from materials and products made with it. 

Formaldehyde can also be released into the air by automobiles, cigarettes, and burning wood, 

kerosene or natural gas. It is also a naturally occurring substance.

Why Should You Be Concerned?

Formaldehyde exposure may potentially cause a variety of symptoms and adverse health effects, 

such as eye, nose, throat, and skin irritation, coughing, wheezing, and allergic reactions. Longterm exposure to high levels of formaldehyde has been associated with cancer in humans and 

laboratory animals. Formaldehyde can affect people differently. Some people are very sensitive 

to formaldehyde at a certain level while others may not have any noticeable reaction to the same 

level.

Formaldehyde is just one of several gases present indoors that may cause adverse health effects 

and illnesses. Many other gases, as well as respiratory illnesses (e.g., colds and the flu), can 

cause similar symptoms to those caused by formaldehyde.

What Levels of Formaldehyde Are Present in Consumer Environments?

Formaldehyde is normally present at low levels, usually less than 0.03 parts per million (ppm), in 

both outdoor and indoor air. The outdoor air in rural areas has lower concentrations while urban 

areas have higher concentrations (due to sources such as automobile exhaust). Residences or 

offices that contain products that release formaldehyde into the air can have levels greater than

0.03 ppm.
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Categories Results

Formaldehyde source Products with sealed surfaces or edges emit1

less

Products with larger surface areas or those treated with 

certain finishes (i.e., acid-cured) have potentially 

increased emissions

Emissions generally decrease as the product ages

Temperature Increased emissions with increased temperature

Lowered emissions with lower temperature

Humidity Increased emissions with increased humidity

Lowered emissions with lower humidity

Air exchange rate

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Increased formaldehyde buildup with a decreased rate

Ambient outdoor or indoor

ozone concentration

Increased creation of formaldehyde in houses that 

ventilate with:

o Outdoor air on days with high levels of pollution

(i.e., ozone-action days)

o Portable or in-duct devices that intentionally emit 

ozone into the air or as a chemical by-product

What Affects Formaldehyde Levels in Indoor Air?

Formaldehyde levels in indoor air can vary depending on temperature, humidity, and air 

exchange rate within the indoor space. In addition, several studies have shown that, in the 

presence of ozone, formaldehyde levels increase; therefore, the outdoor and indoor ozone levels 

are also relevant. Formaldehyde levels in a residence may change with the season, day-to-day, 

and day-to-night. Levels may be high on a hot and humid day and low on a cool, dry day. 

Understanding these factors is important when one is considering measuring formaldehyde 

levels.

1 Release

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The amount of outdoor air entering or leaving the indoor area

What are Some Historical Sources of Indoor Formaldehyde Emissions?

Urea-formaldehyde foam insulation (UFFI): During the 1970s, UFFI insulation was very 

popular, and many homeowners installed it to save energy. A substantial number of these homes 

had high levels of formaldehyde in the indoor air soon after installation; however, these levels 

decreased rapidly after the first few months and reached background levels a few years later. 

Recently, another urea-formaldehyde (UF) spray foam product has been used for insulation. It is 

technically classified as a UF material, but it is functionally different from UFFI. Previously, 

UFFI materials were made of liquid resins with more formaldehyde to maintain their shelf lives, 

which was directly responsible for the off-gassing issues associated with it. This recent UF spray 

foam product’s liquid resin is produced by reacting controlled amounts of urea and formaldehyde 

and then drying the liquid to remove any VOCs, including free formaldehyde. Therefore, less 

formaldehyde would be expected to be released.

Durable-press fabrics, draperies and coated paper products: In the early 1960s, several 

allergic reactions to formaldehyde were reported from the use of durable-press fabrics and coated
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paper products. Such reports have declined in recent years as industry has taken steps to reduce 

formaldehyde levels, and a recent investigation by the Government Accountability Office (2010) 

demonstrated only a small number of clothing items with low formaldehyde levels.

What are the Major Sources of Indoor Formaldehyde Emissions in Our Homes Today?

Measuring formaldehyde emissions from individual consumer products is difficult because a 

variety of products in the home can release formaldehyde or trap formaldehyde emitted from 

other sources. Products with greater emissions and larger surface areas in the home will most 

likely have a greater contribution to indoor air formaldehyde levels. Keep this in mind when 

prioritizing the different product types below. Also, not all brands within each product type 

contain formaldehyde.

Wood floor finishes: Wet commercial, base- and top-coat floor finishes.

• May emit high levels of formaldehyde.

• Emissions decrease 24 hours after application.

• Finishes are not typically available to the consumer, but they can be (re-) applied by 

commercial floor contractors at residences or factories.

Pressed-wood and wood-based products: Pressed-wood (i.e., hardwood plywood, 

particleboard, and medium-density fiberboard (MDF)) and wood-based products, especially 

those containing UF resins, may be a significant formaldehyde source.

• Formaldehyde emissions from pressed-wood products have been reduced 80-90% from 

levels in the 1980’s and earlier due to mandatory formaldehyde emission standards in 

California and national voluntary formaldehyde emission standards, which are described 

later in this booklet.

• Emissions decrease 6-10 months after initial testing.

Wallpaper and paints:

• Moderate levels of formaldehyde initially following application.

• Levels formed during the curing process may be higher than after initial application.

• Emissions are sometimes still detectable 1-3 months following application.

• Some paints are now found with low-VOC formulations.

Combustion: Cigarette smoke and the combustion of other materials, such as wood, kerosene, 

oil, natural gas, and gasoline, produce formaldehyde.

Other materials: Formaldehyde can be created from the chemical reaction between ozone and 

other VOCs during the use of personal computers, laser printers, and photocopiers.

Re-emitters: Because they are porous, products, such as carpets or gypsum board, do not 

contain significant amounts of formaldehyde when new. However, they may trap formaldehyde 

that is emitted into the air from other products and later release it into the indoor air.
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What are Some of the Symptoms and Potential Adverse Health Effects of Formaldehyde

Exposure?

Formaldehyde exposure can cause a variety of symptoms and potential adverse health effects. A 

person’s ability to smell a chemical odor, such as formaldehyde, does not always mean that the

levels of the chemical are of concern or will cause an adverse health effect. Therefore, some 

people can smell formaldehyde before being adversely affected by it.

Affected

Areas/Systems

Potential adverse health effects

Eyes • Stinging, burning, or itching

• Excessive tearing

Nose or throat • Stinging, burning, or itching

• Sore throat

• Runny nose

• Blocked sinuses

• Sneezing

• Cancer (human and laboratory animals)

Respiratory • Chest tightness

• Wheezing

• Asthma

Skin • Allergic contact dermatitis

o Skin rashes, blisters, and flaky dry skin

Neurological • Headaches

• Mood changes (i.e., depression, irritability)

• Insomnia

• Attention deficit

• Nausea

• Impairments in dexterity, memory, and equilibrium

Do You Have Formaldehyde-Related Symptoms?

As discussed above, formaldehyde can induce several symptoms, such as watery eyes, runny 

nose, burning sensations in the eyes, nose, and throat, and headaches. These symptoms may also 

occur because of the common cold, the flu, or other pollutants that may be present in the indoor 

air. In general, if your symptoms lessen when you are away from the home or office but re-occur 

upon your return, they may be caused by indoor air factors including pollutants, such as 

formaldehyde.

Examine your environment. Ask yourself a few questions to determine if your symptoms may be 

related to formaldehyde exposure.

* Have the flooring or cabinets recently been refinished?

* Has remodeling occurred using pressed-wood products (i.e., wall paneling)?
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* Have new cabinets, wall coverings, or furniture been installed?

* Has a wood-burning stove or other combustion source been used?

* Has an indoor air-cleaner that intentionally generates ozone been used?

* Have you recently worn new, unlaundered crease-, stain-, or static-resistant clothes?

* Do you or others smoke indoors?

* Has your house been tightly insulated recently for energy efficiency?

If the answer is yes to any of these questions and you have re-occurring symptoms as described 

above, you could have been exposed to formaldehyde. Therefore, you may want to contact your 

physician and/or state or local health department for further assistance.

How Do You Reduce Existing Formaldehyde Levels?

The choice of methods used to reduce indoor air formaldehyde levels is unique to each situation. 

The most common methods used include:

Remove formaldehyde-emitting products from your home

• Directly reduces formaldehyde levels

• Prevents other materials in the area, such as carpet and gypsum board, from absorbing 

and then re-emitting formaldehyde

Bring large amounts of fresh air into the home

• Increases ventilation by opening doors and windows and by using an exhaust fan(s) to air 

out indoor spaces.

Seal the surfaces of formaldehyde-emitting products that are not already laminated or 

coated

• Use a vapor barrier, such as some paints, varnishes, or a layer of vinyl or polyurethanelike materials

• Seal completely with a material that does not contain formaldehyde

• Many paints and coatings emit other VOCs when curing; therefore, ventilate the area well 

during and after treatment

Install “manufactured-home,” pressed-wood products

• Made with composites meeting the Ultra Low Emission Formaldehyde (ULEF) or No

Added Formaldehyde (NAF) requirements; formaldehyde emission from NAF is less 

affected by increased temperature and humidity than ULEF. 1

Additional specific advice can be obtained from your state or local health department, physician, 

or professional experts in indoor air quality.

1 NA-based resins are resins formulated with no added formaldehyde. ULEF resins are formaldehyde-containing 

resins formulated such that the formaldehyde emissions from composite wood products are consistently below 

applicable California emission standards. See http://www.arb.ca.gov/toxics/compwood/naf_ulef/naf_ulef.htm for 

more information.
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One method NOT recommended by CPSC is a chemical treatment with strong ammonia (28-

29% ammonia in water), which results in a temporary decrease in formaldehyde levels. We 

strongly discourage such treatment because ammonia in this strength is extremely 

dangerous to handle. Ammonia may damage the brass fittings of a natural gas system, adding a 

fire and explosion danger.

How Do You Reduce Your Exposure to Formaldehyde?

CPSC, the Department of Housing and Urban Development (HUD), the Environmental 

Protection Agency (EPA), and other federal agencies have historically worked with pressedwood and other formaldehyde-using industries to reduce the content and release of formaldehyde 

from their products. As discussed earlier, levels in some products that were historically high have 

been substantially reduced.

However, many people deliberately or unknowingly come in contact with other products that 

contain formaldehyde on a daily basis. For most people, a low-level exposure to formaldehyde 

will not produce any adverse effects. For sensitive people, however, the effects may be different. 

If you are sensitive to formaldehyde, you will need to avoid many of these everyday items to 

reduce the possibility of suffering from symptoms.

You can reduce exposure to high levels of formaldehyde by:

* Installing wood floors or finishes that are not “acid-cured”, which is a type of finish that is 

formaldehyde-based.

* Installing pressed-wood products, such as particleboard, MDF, or hardwood plywood, for 

construction or remodeling of homes or for do-it-yourself projects that are labeled or stamped in 

compliance with the American National Standards Institute (ANSI) or California Air Resources 

Board Air Toxics Control Measure (CARB ACTM) criteria.

• Particleboard should conform to ANSI A208.1-2009 (label designated “-F18” or “-F09” 

(Grade D2) or “-F20,” “-F18”, or “-F09” (Grade D3)) or the CARB ACTM.

• MDF should conform to ANSI A208.2-2009 (label designated with “-F21” or “-F11” for 

MDF > 8 mm thickness; “-F21”or “-F13” for MDF ≤ 8 mm thickness) or the CARB 

ACTM.

• Hardwood plywood should conform to ANSI/HPVA HP-1-1994 or the CARB ACTM.

• The Composite Panel Association (CPA) or Hardwood, Plywood, and Veneer 

Association (HPVA) stamps (examples below) also certify that products conform to the 

ANSI standards. These standards all specify lower formaldehyde emission levels.
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* Installing furniture or cabinets that contain a high percentage of panel surface and edges that 

are laminated or coated. Unlaminated or uncoated (raw) panels of pressed wood products will 

generally emit more formaldehyde than those that are laminated or coated.

* Installing alternative products not made with urea-formaldehyde glues, such as wood lumber 

or metal.

* Installing “manufactured-home”, pressed-wood products bonded with a phenol-formaldehyde 

resin system or other pressed-wood products made with composites meeting the ULEF or NAF 

requirements.

* Installing insulation that is not based on UF foam.

* Avoiding high household temperatures.

* Maintaining humidity in the house at 40-50% by:

• Installing or using exhaust fans where moisture is generated

• Using dehumidifiers in humid climates

• Reducing moisture in crawlspaces or basements (i.e., constructing appropriate drainage 

or applying vapor barriers)

• Not using humidifiers or other products to add moisture to already humid air

* Washing durable-press fabrics before use and not choosing clothing and fabrics that are likely 

to contain formaldehyde, such as rayon, blended cotton, corduroy, wrinkle-resistant 100%

cotton, shrink-proof wool, and heavy stiff fabrics.

Should You Test for Formaldehyde?

It should not be necessary to measure formaldehyde in your indoor air if you reduce existing 

formaldehyde levels and do not introduce products that emit formaldehyde into your home. 

However, if you become ill following installation of a product that has been manufactured with 

formaldehyde, you should consult a physician to determine whether or not your symptoms might 

relate to indoor air quality problems. If your physician believes that you may be sensitive to 

formaldehyde, you may want to have the levels of formaldehyde measured.
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There are three different ways to measure formaldehyde in indoor air.

1. Indoor air professional: Indoor air quality (IAQ)-related issues can be complex and are 

often related to building design and function. Trained professionals can:

• Accurately sample for formaldehyde using a variety of methods (some which are not 

generally available to consumers)

• Control or account for complex factors (home closure, standard temperature/humidity 

and sample number/location/duration) that might affect formaldehyde levels

• Interpret the results

• Determine if additional sampling is necessary

Currently, there are no state or federal certification programs for IAQ professionals except for 

lead and asbestos. Therefore, before hiring an IAQ professional, collect information on your IAQ 

problem.

When interviewing IAQ professionals, consider the following questions:

* Have they performed similar jobs, and what were the outcomes?

* Will they include a written report with the data including recommendations?

* Do they have client references with similar IAQ issues?

* Do they have certifications and/or memberships in IAQ- related organizations (see below), 

and what do these certifications or memberships mean?

• American Board of Industrial Hygiene Certified Industrial Hygienist (CIH)

• Board of Certified Safety Professionals’ Certified Safety Professional (CSP)

• American Indoor Air Quality Council-Certified Indoor Environmental Consultant 

(CIEC), Certified Indoor Environmentalist (CIE), or a Certified Indoor Air Quality 

Manager (CIAQM)

• American Industrial Hygiene Association member

• Indoor Air Quality Association member

• Institute of Inspection Cleaning and Restoration Certification member

• American Council for Accredited Certification member

Be cautious of persons or businesses advertising formaldehyde testing - there may be unqualified 

or dishonest individuals seeking to take advantage of consumers. State and local health 

departments or regional US EPA offices may have listings of licensed professionals in your area.

2. Consumer sampling kits: These kits provide a sample vial or badge (passive sampler) that 

must be opened and then attached to or hung in a representative area for a prolonged period 

of time (1-7 days). Following sample collection, the sampler is sealed and mailed to a lab for 

analysis. Currently, labs are available in the U.S. for analyzing passive samplers.

As with IAQ professionals, sampling kits can vary in their ability to detect formaldehyde. In 

general, the buyer should consider the following questions before buying a sampler kit:

* Is the test based on a known method for assessing formaldehyde in air (i.e., NIOSH 3500)?
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* Has the test been validated by a reputable laboratory? In searching for a reputable laboratory, 

consider the following:

• Accreditation by the Industrial Hygiene Laboratory Accreditation Program (IHLAP) of 

the American Industrial Hygiene Association (AIHA)

• Participation in a Proficiency Analytical Testing (PAT) program collaboratively 

sponsored by AIHA and the National Institute for Occupational Safety and Health 

(NIOSH)

* Does the test have a low detection limit (≤ 20-30 ppb)?

* Does the test have good accuracy (± 20 %)?

* Does the test have minimal interference from other chemicals, such as VOCs or ozone?

* Does the test have very specific instructions on where to place the sampler and for how long?

* Does the test include a detailed report with potential recommendations?

* Does the test include technical support?

3. Consumer Sampling and Analysis Kits: At least one type of combined sample and 

analysis test kit is available for formaldehyde that provides a one-time reagent and test 

protocol to analyze for atmospheric formaldehyde without sending the sample off to a lab. 

This combined kit requires the user to carefully follow instructions and is useful for shortduration exposures only. The accuracy of this combined sampling and analytical test kit is 

unknown. The buyer should consider the same questions above before buying combined 

sampler and analysis kits.

Although many air sampling or analysis kits advertise accuracy ranging from 2 to 10 ppb of 

formaldehyde, these claims may not be supported by rigorous testing or scientific analysis using 

standard laboratory methods. Also, test results may be difficult to interpret. Home test kits have 

never been evaluated by CPSC, and therefore CPSC takes no position on the practical use of test 

results from such kits.

For more information about formaldehyde, biological pollutants, combustion pollutants, 

asbestos, and indoor air quality in your home, write or call:

U.S. Consumer Product Safety Commission

4330 East West Highway

Bethesda, MD 20814

CPSC’s toll-free hotline: 800-638-2772 (TTY 301-595-7054) 

CPSC’s web site: http://www.cpsc.gov

The following references provide more formaldehyde information: 

http://www.epa.gov/formaldehyde

http://www.cdc.gov/niosh/topics/formaldehyde/
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References

The following additional references can be consulted to obtain more information on product emission rates, healthrelated issues, and regulatory and voluntary standards for formaldehyde.

California Environmental Protection Agency - Air Resources Board. 2004. Indoor air quality guideline: 

Formaldehyde in the home. http://www.arb.ca.gov/research/indoor/formaldGL08-04.pdf. 16pp.

Composite Panel Association. 2009. American National Standard: Particleboard; ANSI A208-.1-2009; Composite 

Panel Association. Leesburg, VA. 12pp. 

http://www.nssn.org/search/DetailResults.aspx?docid=651906&selnode=Composite Panel Association. 2009.

American National Standard: Medium Density Fiberboard (MDF) for Interior Applications; ANSI A208-.2-2009; 

Composite Panel Association. Leesburg, VA. 22pp. 

http://www.nssn.org/search/DetailResults.aspx?docid=651907&selnode = 

Residential Indoor Air Quality Guideline: Formaldehyde. http://www.healthycanadians.gc.ca/publications/healthyliving-vie-saine/formaldehyde/index-eng.php

Hardwood Plywood & Veneer Association (HPVA). 1994. American National Standard: Hardwood and Decorative 

Plywood. ANSI/HPVA HP-1. 1994. 25pp. http://www.nssn.org/search/DetailResults.aspx?docid=1091704&selnode= 

Frey, S.E., Destaillats H., Cohn S., Ahrentzen S., and Fraser M.P. 2014. Characterization of indoor air quality and 

resident health in an Arizona senior housing apartment building. Journal of the Air & Waste Management Association 

64(11):1251-1259. http://www.ncbi.nlm.nih.gov/pubmed/25509546

Hult E.L., Willem H., Price P.N., Hotchi T., Russell M.L., and Singer B.C. 2015. Formaldehyde and acetaldehyde 

exposure mitigation in US residences: in-home measurements of ventilation control and source control. Indoor Air 

25:523-535. http://www.ncbi.nlm.nih.gov/pubmed/?term=Hult+AND+formaldehyde

Hun D.E., Corsi R.L., Morandi M.T., and Siegel J.A. 2010. Formaldehyde in residences: long-term indoor 

concentrations and influencing factors. Indoor Air 20:196-203. http://www.ncbi.nlm.nih.gov/pubmed/20408902

Kelly, T.J., Smith, D.L., and Satola, J. 1999. Emission rates of formaldehyde from materials and consumer products 

found in California homes. Environ. Sci. & Technol. 33:81-88. http://pubs.acs.org/doi/abs/10.1021/es980592%2B

Mason, M, Xiaoyu L, Krebs, K, and Sparks, L. 2004. Full-Scale Chamber Investigation of Air Freshener Emissions. 

Journal of Environmental Science and Technology. 

Morrison, G.C. and Nazaroff, W.W. 2002. Ozone interactions with carpet: secondary emissions of aldehydes. 

Environmental Science Technology 36: 2185-2192. 

Myers, G.E. 1986. Effects of post-manufacture board treatments on formaldehyde emission: a literature review 

(1960-1984). Forest Products Journal. 36(6):41-51. http://www.fpl.fs.fed.us/documnts/pdf1986/myers86a.pdf

Salthammer, T., Mentese, S., and Marutzky, R. 2010. Formaldehyde in the indoor environment. Chem. Rev. 110(4): 

2536-2572. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2855181/. 

Toxics Use Reduction Institute (TURI). 2006. Five Chemicals Alternative Assessment Study. Formaldehyde. 

42pp. 

http://www.turi.org/TURI_Publications/TURI_Methods_Policy_Reports/Five_Chemicals_Alternatives_Assessment_

Study._2006/Full_Report

U.S. Agency for Toxic Substances and Disease Registry. 2010. Formaldehyde ToxFAQs. 

http://www.atsdr.cdc.gov/toxfaqs/tfacts111.pdf . 2pp. 
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U.S. Environmental Protection Agency. 2010. Toxicological review of formaldehyde inhalation toxicity (External 

Review Draft): In support of summary information on the Integrated Risk Information System (IRIS). EPA/635/R10/002A.. http://cfpub.epa.gov/ncea/iris_drafts/recordisplay.cfm?deid=223614. 

U.S. Government Accountability Office. 2010. Report to Congressional Committees. Formaldehyde in textiles: While 

levels in clothing generally appear to be low, allergic contact dermatitis is a health issue for some people. 

http://www.gao.gov/new.items/d10875.pdf . 53pp. 

Weschler, C. J., Hodgson, A.T., and Wooley, J. D. 1992. Indoor Chemistry: Ozone, Volatile organic compounds and 

carpets. Environmental Science Technology 26: 2371-2377. 

http://faculty.rmu.edu/~short/research/formaldehyde/index.htm

World Health Organization. 2010. WHO Guidelines for Indoor Air Quality: Selected Pollutants. 3. Formaldehyde. 

http://web.jrc.ec.europa.eu/radpar/docview.cfm?docid=104. p103-156.
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U.S. CONSUMER PRODUCT SAFETY COMMISSION

4330 EAST WEST HIGHWAY 

BETHESDA, MD 20814