Formaldehyde (methanal, methyl aldehyde or methylene oxide) is a chemical compound with the formula CH2O. Formaldehyde is a colorless, strong-smelling pungent gas. Aqueous solutions of formaldehyde are referred to as formalin. Formalin consists of an aqueous solution of formaldehyde, usually containing about 37% formaldehyde and 12-15% of methanol. Formalin is best known as an embalming fluid in anatomy labs and morgues.
Formaldehyde is one of the most commonly used toxic substances. Although it is not directly used as a household product, it takes part in the production of a vast number of everyday goods, including cosmetics, textile and even food and medical supplies, such as vaccines. However, the toxicity of formaldehyde is quite serious: its ingestion can be fatal and inhalation and skin contact can cause serious injuries. It is also a sensitizer toward allergic reactions. It has been evidenced on animals that it is carcinogenic and it is suspected to be carcinogenic to humans as well. For this reason, even minuscule quantities of formaldehyde are dangerous, because allergy and cancer do not need much - just a trigger. And additionally: poison is poison. It just harms you less acutely when in small doses, but still damages your cells. However, the overall use of formaldehyde is actually not small at all. The annual world production of formaldehyde (about 2005) was 21 million tonnes, or 46 billion pounds. Nowadays Europe alone produces 33 million tones. This means that each and every person on Earth “receives” several pounds of formaldehyde yearly. This is a massive amount of a toxic substance. Where does it go? Are we exposed to it? Just very recently, the Formaldehyde Council Inc. (FCI), which represents the formaldehyde industry, exclaimed that “Knowledgeable scientists familiar with the vast research database on formaldehyde agree that at the low levels of the chemical to which people are normally exposed, either through internal or external sources, there is essentially no risk”. But – risk of what specifically? The problem with formaldehyde is that it is a small, volatile molecule, which evaporates easily. Therefore, the “small dose” in a product by weight can become acutely harmful when evaporated and inhaled. Studies have shown that people experience sensory irritation (eye, nose and respiratory tract irritation) at levels in air as low as 0.5 ppm (part per million i.e. less than one formaldehyde molecule per one million air molecules). Formaldehyde is an essential constituent of the so called Volatile Organic Compounds (VOC), which cause serious air pollution. Many building materials such as paints, adhesives, wall boards, and ceiling tiles emit formaldehyde, which irritates the mucous membranes, leading to the so called Sick Building Syndrome (SBS). The infamous case of Hurricane Katrina, where the victims were subjected to poisoning by formaldehyde in their mobile homes provided by FEMA in 2006, shows how freshly produced construction materials which are contained in a small space without sufficient ventilation can create acute poisoning from formaldehyde exposure. The advice from the US Environmental Protection Agency to the consumers is just to ventilate your homes more frequently, reduce the indoor temperature and humidity in order to reduce the evaporation of formaldehyde. At the same time, FCI criticizes the media for unsoundly dramatizing the dangers of formaldehyde and states for example that “Numerous others described household products that are “formaldehyde-free” as “healthier” – although that too is scientifically and medically unproven”. Another statement from FCI is that “getting cancer from cabinets containing urea formaldehyde is physiologically impossible”, while the governmental regulations state that formaldehyde is a suspected carcinogen in humans. Moreover, the OSHA requires that for all materials capable of releasing formaldehyde at levels above 0.5 ppm during normal use, the label must contain the works “potential cancer hazard.”
Fortunately, it is still for the consumers to decide whether they believe that poison-free products can be actually healthier, even without having “the scientific and medical proof”. However, in order to make such a decision, we need to know more about the formaldehyde properties and its actual uses, while the industrial lobby seems to be concealing the magnitude of the health problem.
Several European countries restrict the use of formaldehyde, including the import of formaldehyde-treated products and embalming, and the European Union is considering a complete ban on formaldehyde usage.


Formaldehyde has been classified by National Occupational Health and Safety Commission (NOHSC) as a Category 2 carcinogen (may cause cancer by inhalation). Other classifications that remain applicable are: toxic by inhalation, in contact with skin and if swallowed, causes burns, and may cause sensitisation by skin contact.

Toxicity of formaldehyde

(based on the information in the US Toxicology Database Network (TOXNET) and US National Library of Medicine)

Ingestion of formaldehyde can be fatal. If solution is ingested, mucous membranes of mouth, throat, and intestinal tract are irritated with severe immediate pain in the mouth and pharynx, causing abdominal pains with nausea, vomiting and diarrhea, loss of consciousness, coma and even death due to respiratory failure. After absorption, formaldehyde depresses central nervous system and symptoms not unlike those of alcohol intoxication are noted. They consist of vertigo and depression. Rarely convulsions are observed. Circulatory collapse and kidney damage may also occur soon after ingestion. Severe lung changes may result from aspiration of the ingested compound in combination with stomach acid. Degenerative changes may be found in the liver, kidneys, heart and brain. Fatal cases of suicidal use of formalin have occurred. The lethal dose has been estimated to be 523 mg/kg of formalin (37% solution of formaldehyde).

Formaldehyde liquid (formalin) is corrosive and contact with the skin causes irritation, tanning effect, and skin burns. Contact with eyes causes irritation, itching and lacrimation. Aqueous solutions splashed or dropped on human eyes have caused injuries ranging from severe permanent corneal opacification and loss of vision to minor transient injury or discomfort, depending upon whether solutions were of high or low concentration.

Formaldehyde vapor is very irritating to the mucous membranes. Acute exposure is highly irritating to the eyes, nose, throat, skin and respiratory system, causing coughing and sneezing. Symptoms related to inhalation include: rhinitis, anosmia, laryngospasm, tracheitis, and gastroenteritis. Formaldehyde may elicit a respiratory response in some very sensitive, individuals with bronchial hyperactivity, probably through irritation of the airways.

Formaldehyde is a strong sensitizing agent that can cause an immune system response upon initial exposure. Subsequent exposure may cause severe allergic reactions of the skin, eyes, and respiratory tract and long-term exposure to low levels in the air or on the skin can cause asthma-like respiratory problems and skin irritation such as dermatitis and itching. Formaldehyde allergy with eczematoid dermatitis is common and usually derives from formaldehyde-releasing biocides in cosmetic and other products. A recent (2008) study showed that allergy to formaldehyde-releasing preservatives in liquid soaps and other rinse-off products was common in both occupational and non-occupational cases. Dermatitis from clothing treated with formaldehyde (such as anti-wrinkle or perma-press textile) has also occurred.

Based on the available nasopharyngeal cancer data, formaldehyde should be regarded as if it may be carcinogenic to humans following inhalation exposure. There are also concerns of an increased risk for formaldehyde-induced myeloid leukaemia, however, the data are not considered sufficient to establish a causal association. Although human data is still limited, animal testing shows a confirmed carcinogenic link.
Formaldehyde is also considered to have weak genotoxic potential.

Hazardous Substances Databank recommendation:

”Because formaldehyde solutions may induce skin sensitisation and even very low concentrations of formaldehyde in solution may elicit a dermatological reaction in individuals who have been sensitised, dermal exposure should be minimised or prevented wherever possible”.

Sources of exposure
General population may be exposed to formaldehyde via inhalation of air (indoor and outdoor), ingestion of food, and dermal contact with cosmetic and aerosol products containing formaldehyde. On top of this, formaldehyde is emitted to the air from the combustion process, specifically from auto emissions, from the photooxidation of hydrocarbons in auto emissions, as well as gas or wood combustion in stoves.

Formaldehyde may be present in many household products. According to the current US regulations, the manufacturers do not have to disclose its presence on the label if the content of formaldehyde does not exceed 0.01%. But this is only if formaldehyde constitutes an “intentional component”. They do not have to reveal it, if it is introduced for example as a solvent, preservative or stabilizer of another component.
Detergents, cosmetics and other domestic chemicals (shampoos, hair conditioners and bubble baths, nail polish, dyes, room deodorants dish-washing liquids, ,fabric softeners) often contain formaldehyde as an antimicrobial agent. It is used as disinfectant and antibacterial food additive.

It is also found in glues and adhesives, wallpaper, shoe-care agents, carpet cleaners, glues and, lacquers, water-based paint, lubricants, foam rubber, insulating, automotive components, fertilizers, latex, leather, paper.

Phenol-formaldehyde resins find use as adhesives for binding wood products (particle board, fiber board, and plywood). Melamine-formaldehyde resins are used in decorative laminates, thermoset surface coatings, and molding compounds such as dinnerware. In medicine, many vaccines contain formaldehyde, as well as hard gelatin pill coating. Formaldehyde-based resins and adhesives are in permanent press and other finish of fabrics (clothing, even for babies’ (!) draperies), grocery bags and waxed paper.

Recently, FDA approved the use of formaldehyde in the chicken feed to fight salmonella.
It has been also proven that aspartame in the Diet Cola decomposes into formaldehyde if not refrigerated.

Examples of products containing formaldehyde

(according to the Household Product Database of US department of Health & Human Services)

Gerber Baby Wash With Lavender - 15 Fl. Oz., Softsoap Body Wash, Ultra Rich Shea Butter, Softsoap Advanced Moisture Cashmere Liquid Hand Soap, Irish Spring Body Wash, Aloe, Softsoap Body Wash, Pure Cashmere, Softsoap Shea Butter Liquid Hand Soap, Palmolive Aromatherapy Liquid Hand Soap, Irish Spring Body Wash, Icy BlastElmers Probond Exterior Wood Glue-09/14/2001, Aleenes School Glue, DAP Latex Window Glazing Paste, Titebond II Premium Wood Glue, Knauf Duct Liner EM, Knauf Foil-Faced Residential Insulation, Knauf Insulation Board, Knauf Sill Sealer, Elmers Probond Exterior Wood Glue, Franklin Laminate Flooring Glue, Knauf Basement Wall Insulation, Knauf Friendly Feel Duct Wrap, Unfaced and Faced, Knauf FSK-Faced Residential Insulation, Knauf Kraft-Faced Residential Insulation, Knauf Wall Insulation, Quikrete Concrete Bonding Adhesive, Quikrete Concrete Repair, , Hagen Flea and Tick Shampoo for Cats, Tetra Plant Flora Pride Iron Intensive Fertilizer, Zodiac Organique Foam Shampoo for Dogs, Tetra Aquarium Betta Safe, Tetra Aquarium Aqua EasyBalance with Nitraban, Tetra Aquarium Blackwater Extrac, Tetra Pond Barley & Peat Extract, agen Tearless Shampoo for Cats, Zodiac Organique Foam Shampoo for Cats
Tetra Aquarium AquaSafe for GoldfishTetra Aquarium Plant FloraPride-08/17/2007Tetra Pond Fish Treatment, Tetra Pond FloraFin

For these products, the Household Product Database has provided Material Safety Data Sheets (MSDS) which are prepared by the manufacturer. MSDS provides vital information on the safety of the product, but actually it normally does not reach the consumer.

Check the first example on the list: Gerber Baby Wash. It might be expected to be safe for babies. See the actual excerpts form the MSDS of the Gerber Baby Wash:

Warning: Keep this product out of reach of children. For external use only.

Emergency Overview:
Eye: Mild irritant.
Skin: Mild-moderate irritant.

Potential Health Effects:
EYE: [as determined by in-vitro testing] Rated as mild irritant. May cause slight redness and tearing in a selected portion of the population.
SKIN: [as determined by in-vitro testing] Rated as mild-moderate irritant. Very low dermal toxicity anticipated. May cause slight irritation in a selected portion of the population.
ORAL TOXICITY: LD50 >= 5 g/kg rat-(non-toxic) [as determined by computer simulation]. This product has not been tested on animals.
INHALATION: Not likely. Mists are unlikely to form, but may cause upper respiratory irritation.

Medical conditions that may be aggravated by exposure: Prolonged skin contact may aggravate existing skin condition

Although the majority of the products contain formaldehyde at low concentrations (< 0.2%), the accumulation of the daily dose becomes truly significant when multiplied by the number of products that we came in contact with every day. It simply ads up: a fraction of percent in a shampoo, in a body wash, in a kitchen cabinet, in glue… It seems that it is quite easy to really use up your several pounds of formaldehyde yearly