Q & A on formaldehyde

What is formaldehyde?
Where does formaldehyde come from?
Why do we need formaldehyde?
Where is formaldehyde found in nature?
Where and how do we as industry use formaldehyde?
Is formaldehyde carcinogenic for humans?
What does science say about formaldehyde?
Do we need to worry about exposure to formaldehyde?
What levels of formaldehyde are safe?
How is formaldehyde classified by the EU?
What would a reclassification mean for industry and society?
What is industry’s role in increasing our knowledge on formaldehyde?
How do we as FormaCare understand industry’s responsibility?
What is IARC and what conclusion has it reached on formaldehyde?
Where can I get additional information?

1. What is formaldehyde?

Formaldehyde is a naturally occurring substance which was discovered in 1867 and can be found all around us at low levels, and as such is not dangerous. Formaldehyde is present in most life forms such as human, animals, plants etc. All normally functioning cells produce and use formaldehyde and you can even find formaldehyde in outer space! You breathe it in and eat it every day.

Formaldehyde is a natural metabolic intermediate and is produced by all living cells. The natural concentration of formaldehyde in the blood of humans and mammals is 3 mg/kg. In some cells of the human body, e.g. liver cells or in the epithelial cells of the nasal mucosa, concentrations of formaldehyde can exist at up to 6-12 mg/kg. Formaldehyde is broken down by sunlight and bacteria within a few hours and is quickly decomposed during the human metabolism process. This is why formaldehyde neither accumulates in the human body nor in the environment.

Formaldehyde is not only readily found in nature, but is also an exceptional and flexible substance when manufactured that has many important uses, particularly when creating polymers and other substances that are essential for living in a contemporary world (please see also Q5 - Where and how do we as industry use formaldehyde?). Formaldehyde is a natural product and a safe chemical under today’s exposure limits that has hundreds of practical uses in our daily lives – from good cell function to the foods we eat to the products we use.

2. Where does formaldehyde come from?

Formaldehyde is a naturally occurring substance and can be found all around us at low levels, which are not dangerous to humans. Formaldehyde is formed in the nature as a result of photochemical processes from the oxidation of methane in the atmosphere. Methane is the key compound to its production and also a basic raw material used when producing formaldehyde synthetically from methanol. It is made up of oxygen, hydrogen and carbon. Where livestock and agriculture exist, you will find measurable amounts of naturally occurring formaldehyde. Human activities such as the operation of motors or cooking and heating with gas also result in the release of formaldehyde. It is also released during forest and bush fires. Formaldehyde can be found in everyone’s garden. Apples, a food people eat everyday, naturally contain rather high levels of formaldehyde. Formaldehyde is included in most life forms - human, animals, plants etc.

Formaldehyde is present in many foodstuffs such as fruit, meat and vegetables:

(source: WHO – Environmental Health Criteria 1989 )

Back to top

3. Why do we need formaldehyde?

Formaldehyde is an important and crucial base chemical used in a wide range of production processes that are essential for our modern way of living. Formaldehyde is a raw material for glues/polymers that is required for the production of multiple goods. As you can see in the “house of glues” below, it plays an important role in the production of furniture, household products, fabrics, kitchen articles, sporting articles, shoes, paints and coatings, lubricants, hydraulic fluids, foam rubber, insulating, automotive components, textiles, paper, pharmaceuticals, prostheses, disinfectants and many other products. See also questions 4 and 5

By Courtesy of

4. Where is formaldehyde found in nature?

Formaldehyde is formed in the nature as a result of photochemical processes from the oxidation of methane in the atmosphere. Methane is the key compound to its production and also a basic raw material used when producing formaldehyde synthetically from methanol. It is made up of oxygen, hydrogen and carbon. Formaldehyde occurs naturally in the livestock and in agriculture as well as from human activities such as the operation of motors or from gas heating and cooking. It is also released during forest and bush fires. Formaldehyde can be found in everyone’s garden. Apples, a food people eat everyday, naturally contain rather high levels of formaldehyde.

Formaldehyde is not only readily found in nature, but is also an exceptional and flexible substance when manufactured that has many important uses, particularly when creating polymers and other substances that are essential for living in a contemporary world. Formaldehyde naturally decomposes quickly and doesn’t build up in living beings. Formaldehyde is a natural product and a safe chemical under today’s exposure limits that has hundreds of practical uses in our daily lives – from good cell function to the foods we eat to the products we use.

Please see also our benefit story

5. Where and how do we as industry use formaldehyde?

Methods of formaldehyde production have improved over the years as has the variety of uses. Today, industrial applications range from use in healthcare to construction materials and innovation. It can be used in many products as an industrial disinfectant and/or as a preservative.

Formaldehyde is mainly commercially distributed in an aqueous, liquid form, formalin (37 -55%). The main use of formaldehyde is as a raw material in resins, producing a unique glue bond for the manufacturing of items such as furniture, flooring, cabinets, stairs and the like. When applying best practice limits to formaldehyde, emissions from wooden panel boards comprise the European E1 standards of under 0.1 ppm.

Formaldehyde is also an essential raw material in dyes and inks that are used in a variety of publication processes from magazines to newspapers and in photo-copiers. Formaldehyde is also uniquely used in the making of wrinkle free fabrics.

Formaldehyde serves many purposes in many different products. It is used as a part of:

the glue or adhesive in pressed wood products such as particleboard, hardwood plywood, and medium density fibreboard MDF (Link); preservatives in some paints, coatings, and cosmetics;

the coating that provides permanent press quality to some fabrics and draperies;
the finish used to coat paper products;
the polymers to manufacture products such as dashboards for cars (Link)
and because of its biocidal and fungicidal properties, it is also used in the manufacturing of disinfectants, cosmetic conservatives, pharmaceutical antiseptics, etc.

In Europe, the yearly production volume of formaldehyde is 3 million tonnes. The formaldehyde producing industry directly employs 38 000 workers in Europe. 100 000 additional jobs are indirectly related to the European formaldehyde industry. Industries which rely on industrial formaldehyde, such as the wood panels and furniture industry, employ more than 5 million people. More examples include the automotive, construction chemicals, textile or methanol industries.

Please see also our benefit stories .

Back to top

6. Is formaldehyde carcinogenic for humans?

Carcinogenicity is considered to be the ability or tendency of a substance to cause or produce cancer. In the case of formaldehyde however, available scientific data shows that a connection between formaldehyde and cancer is unlikely at today’s levels of occupational and indoor air exposure. Yet doubts exist about formaldehyde's role in a rare form of the disease affecting the upper respiratory tract.

To decide whether a substance is carcinogenic or not, scientists – and therefore policy makers- seek to determine two factors: hazard and risk. “Hazard” means the intrinsic property of a chemical agent with the potential to cause harm. “Risk” means the likelihood that the potential for harm will be attained under the conditions of exposure. The problem is that often a substance is defined as carcinogenic on the basis of hazard and not of risk. For further information, please click here .

Animal experiments with rats showed cancer in the upper respiratory tract in concentrations of between 6 and 15 ppm. Other laboratory animals like mice or hamsters are much less sensitive and did not show tumours at similar exposure concentrations. Those are concentrations no human being would bear, due to the irritating properties which affect the eyes and nose.

The IARC carried out a review in 2004 of a number of epidemiological studies on workers exposed to formaldehyde up to more than 60 years ago. These studies indicated that individuals who were exposed to high doses of formaldehyde showed an increased risk of developing the very rare nasopharyngeal cancer. Therefore, the IARC recommended reclassifying formaldehyde from group 2A -“probably carcinogenic to humans” to group 1 - “carcinogenic to humans” . This recommendation is not legally binding. The monograph substantiating this argument has only recently been published in 2007 . In the preamble to monographs it is explicitly emphasised by the IARC that, “… no recommendation is given with regard to regulation or legislation…”.

The IARC is primarily referring to the three largest so-called “cohort studies” on formaldehyde from 2003 and 2004. Only one of these three studies shows an elevated number of cancer cases in the nasopharyngeal area, and in this one study, only one of the ten manufacturing plants under investigation has shown an above-average accumulation of cases. Overall, 50 000 chemical workers have been observed who were in contact with formaldehyde at the workplace. Nine nasopharyngeal cancers cases have been registered – seven would have been statistically expected for a group of persons who are not in contact with formaldehyde. Ten more years of epidemiological data concerning the NCI (National Cancer Institute) study will become available 2007/2008. A detailed review of the disease cluster observed at this particular plant 1, the manufacturing plant in the US that alone is responsible for almost three fourths of the cases in the NCI study has recently been carried out. Thereby it was shown that exposures in silver smithing and metal industries might have been an important factor for development of this specific tumor type. In addition, a critique of the statistical methods used by NCI has been published concluding that some aspects of the statistical approach are to be challenged scientifically.

It has to be taken into consideration however, that at the time when the workers under investigation were exposed to formaldehyde (up to more than 60 years ago), the Occupational Exposure Limits (OELs) were significantly higher than nowadays.

Occupational Exposure Limits are nowadays established nationally and are set to prevent adverse health effects. As these regulations are followed and closely observed, the risks are very low. Most OELs in Europe are between 0.3 and 0.5 ppm. .

Occupational exposure limits regarding formaldehyde are set in each country by the national labour inspectorates. To obtain more information on Occupational Exposure Limits in your country, please contact the FormaCare Secretariat (formaldehyde@cefic.be) or your national labour inspectorate. For enquiries in North America, please contact the Formaldehyde Council, Inc (mpalla@formaldehyde.org).

Industry is aware formaldehyde needs to be treated with care, due to earlier classifications of formaldehyde [1982 and 1987 (2B) – “Possibly carcinogenic to humans” and 1995 (2A) – “Probably carcinogenic to humans”]. Handling guidelines and legislation have been updated taking into account the latest scientific knowledge and data. In addition, exposure levels of formaldehyde in the workplace have declined dramatically over the past three decades due to improved manufacturing technology and industrial hygiene measures.

Due to constantly improving production methods over the last decades, indoor air levels of formaldehyde have decreased significantly. Studies show that indoor air levels of formaldehyde in homes and offices are nowadays at a safe level below 0,1 ppm.

As in the majority of industrial activities, including the chemicals industry, occupational exposure is greater than domestic exposure. Nowadays indoor air levels rank below 0.1 ppm, so there is virtually no risk for the general population and the end consumer.

Formaldehyde is not only readily found in nature, but is also an exceptional and flexible substance when manufactured that has many important uses, particularly when creating polymers and other substances that are essential for living in a contemporary world. Formaldehyde naturally decomposes quickly and doesn’t build up in living beings. Formaldehyde is a natural product and a safe chemical under today’s exposure limits that has hundreds of practical uses in our daily lives – from normal cell function to the foods we eat to the products we use.

At the EU level, the issue is currently being reviewed (see Q 10: How is formaldehyde classified by the EU?).

For further scientific information, please refer to our Scientific Factsheet – Scientific Update Information.

7. What does science say about formaldehyde?

Available scientific data shows that a connection between formaldehyde and cancer is unlikely at today’s levels of occupational and indoor air exposure. Yet doubts exist about formaldehyde's role in a rare form of the disease affecting the upper respiratory tract.

New studies currently being performed, or already completed, to evaluate formaldehyde’s impact on human health, cover among others the following areas:

Epidemiology. IARC is primarily referring to the three largest so-called “cohort studies” on formaldehyde from 2003 and 2004. Only one of these three studies shows an elevated number of cancer cases in the nasopharyngeal area, and in this one study, only one of the ten observed manufacturing plants has shown an above-average accumulation of cases. Overall, 50000 chemical workers have been observed who were in contact with formaldehyde at the workplace. Nine nasopharyngeal cancer cases have been registered – seven would have been statistically expected for a group of persons who is not in contact with formaldehyde. Ten more years of epidemiological data concerning the NCI (National Cancer Institute) study will become available 2007/2008. A detailed review of the disease cluster observed at this particular plant 1, the manufacturing plant in the US that alone is responsible for almost three fourths of the cases in the NCI study has recently been carried out. Thereby it was shown that exposures in silver smithing and metal industries might have been an important factor for development of this specific tumor type. In addition, a critique of the statistical methods used by NCI has been published concluding that some aspects of the statistical approach are to be challenged scientifically.

The threshold for irritation in humans. A review of the available literature on the irritation of formaldehyde to the eyes and upper respiratory tract of humans by Dr. Arts et al. suggests negligible irritation for concentrations of less than 1 ppm. Another study in human volunteers has been performed at the University of Heidelberg. Thereby under conditions simulating workplace exposure situations no objective signs of irritation were found at concentrations of 0.3 ppm with peaks of 0.6 ppm or 0.5 ppm continuously.
Inportant questions exist about the relationship of genotoxicity and mutagenicity of formaldehyde (see also Scientific Fact Sheet ). Investigations on the relationship of cross-links between DNA and proteins and potential genotoxic and mutagenic effects have been carried out in cell culture. Most importantly it has been demonstrated that DNA-protein cross-links are rapidly repaired and that most likely there is a threshold for induction of mutations.
Animal studies. These studies, designed to quantitatively define the potential cancer risks, will investigate low-dose formaldehyde thresholds for the upper respiratory tract in rats, and will be available by 2007/2008.

In short the results strengthen the previous position of major parts of the scientific community that formaldehyde is a safe chemical provided that the current exposure levels are respected.

8. Do we need to worry about exposure to formaldehyde?

In general terms, exposure is defined as the act of being exposed/subject to a source of risk. When it comes to chemical substances such as formaldehyde, exposure is linked to hazard (see above Q6 – Is formaldehyde carcinogenic to humans? LINK) and defined as the extent to which the recipient of the harm is exposed to the hazard.

Exposure to chemical substance in the work place, more commonly known as occupational exposure, is defined as the likelihood for workers to be exposed to a chemical substance in the work place. The European Commission has also defined the limit of the occupational exposure (OEL – Occupational Exposure limits) as the “limit of the time weighted average of the concentration of a chemical agent in the air within the breathing zone of a worker in relation to a specified reference period” (Directive 98/24/EC).

In over a century of use as a manufactured product, many people have been exposed to formaldehyde at much higher levels than today. Indoor exposure was formerly higher than nowadays. Due to constantly improving production methods over the last decades, indoor air levels of formaldehyde have decreased significantly. Studies show that indoor air levels of formaldehyde in houses and offices are nowadays at a safe level of below 0.1 ppm.

Formaldehyde-concentrations in wood panels are nowadays approaching the range of those in natural wood

Formaldehyde is not only readily found in nature, but is also an exceptional and flexible substance when manufactured that has many important uses, particularly when creating polymers and other substances that are essential for living in a contemporary world. Formaldehyde naturally decomposes quickly and doesn’t build up in living beings. Formaldehyde is a natural product and a safe chemical that has hundreds of practical uses in our daily lives – from normal cell function to the foods we eat to the products we use.

9. What levels of formaldehyde are safe?

Like most other substances formaldehyde is toxic in very high doses. But like Paracelsus said: the dose makes the poison.

Formaldehyde is a natural metabolic intermediate and is produced by all living cells. 3 mg/kg of formaldehyde is the natural concentration in the blood of humans and mammals. In some cells of the human body, e.g. in the liver or in the epithelial cells of the nasal mucosa, concentrations of formaldehyde can reach up to 6-12 mg/kg.

Studies show that indoor air levels (see also Q8- Do we need to worry about exposure to formaldehyde? ) of formaldehyde in houses and offices are nowadays at a safe level of below 0,1 ppm.

Sensory irritation, that is eye and nose irritation, is first observed at levels of 1 ppm and higher. From both human and animal studies it has been concluded in a recent review (JHE Arts (2006) TNO Voeding, in: Reg Tox Pharmacol) that “at airborne levels for which the prevalence of sensory irritation is minimal both in incidence and degree (i.e. < 1 ppm), risks of respiratory tract cancer are considered to be negligibly low.”

The latest Risk Assessment (BfR, German Federal Institute for Risk Assessment) concluded in 2006 that the concentration of 0.1 ppm indoor for general population is proposed as a safe level with regard to the carcinogenicity of formaldehyde in humans,

10. How is formaldehyde classified by the EU?

At the moment, formaldehyde is categorised as a category 3 carcinogen* within the European Union, which is implemented by Member States.

Dangerous Substances Directive - category 3 (C3) carcinogen leading to a risk phrase R 40 (Limited evidence of a carcinogenic effect).

This is the weakest class of carcinogenic hazard.

The EU classification of formaldehyde is currently being reviewed. Based on a French proposal, the discussions are taking place in the European Commission’s Technical Committee on Classification and Labelling (working group of the Member States). 'Hazard’ means the intrinsic property of a chemical agent with the potential to cause harm; 'Risk’ means the likelihood that the potential for harm will be attained under the conditions of use and/or exposure.

The recommendation from the IARC (see also Q14 – What is IARC and what conclusion has it reached on formaldehyde? LINK) in 2004 was to reclassify formaldehyde to a group 1, meaning it is “carcinogenic to humans”. This recommendation is not legally binding.. In the preamble to monographs it is explicitly emphasised by IARC: “… no recommendation is given with regard to regulation or legislation…”.

The NCI (National Cancer Institute) study is currently updated to include data up to 2003, adding an additional ten years of observations to the latest investigation. Because cancer is often a disease of old age, the aging of the workforce will strengthen the data on cancer mortality. This update will be available by 2007/2008. Further studies have been initiated by the formaldehyde industries many of which have already been finalised and published.

Naturally, it is important to take all this new data into account in order to take a well-informed decision on the European level.

11. What would a reclassification mean for industry and society?

As industry, we are committed to public health and responsible care and consider it equally important with the other business segments. Substitution is in many cases very difficult or simply impossible. Furthermore, many possible substitutes are less well-researched and may lead to higher risks. Costs are also significantly higher and calculations show that cost-increases would equal roughly 10 billion Euros per year.

Nowadays safe indoor air concentrations as well as occupational exposure levels are guaranteed and can be easily complied with. Furthermore, there are over 4 million jobs in this industry and the societal benefits of formaldehyde are not easily replaceable.

12. What is industry’s role in increasing our knowledge on formaldehyde?

In order to allow for a comprehensive risk assessment, FormaCare has initiated research programs with several European and American institutes and universities. These studies are dealing with epidemiology, sensory irritation, genotoxicity and mutagenicity. For more information on science, please refer to question 7(LINK): What does science say about formaldehyde? And to our Scientific Fact Sheet – Scientific Update Information

All in all, results of ten new studies are available by now or soon will be which will contribute to a better understanding and a clear assessment of formaldehyde.

To this end, FormaCare organized a two-day International Science Conference in Barcelona. With some of the most distinguished institutes worldwide and representatives from Germany, Sweden, UK, the Netherlands, Israel, USA and Brazil participating, the conference turned out to be one of the most important scientific debates in the history of formaldehyde research. The European Commission chaired one of the main sessions.

So the industry’s role is in increasing our knowledge on formaldehyde by independent research based on sound science and providing the forum to present and discuss these findings between all interested stakeholders.

The benefits of formaldehyde have been employed for well over a century now and it is a very well-researched chemical with a broad database on its effects. Furthermore, industry has made numerous efforts to make an already safe chemical even safer (see also: Scientific Fact Sheet – Scientific Update).

13. How do we as FormaCare understand industry’s responsibility?

The main responsibility of the FormaCare member companies lies with the industry’s employees and with the consumers. Safety in the workplace is crucial and safety measures are regularly controlled and being improved upon. Confident workers have a great impact on the sustainability of the industry sector.

Also important for the FormaCare members is the sustainable use of formaldehyde. Due to constantly improving production methods over the last decades, indoor air levels of formaldehyde have decreased significantly. The promotion of best practice amongst FormaCare members is therefore one of our main target areas. Our members constantly analyse their processes to improve eco-efficiency, to get higher yields out of raw materials, to reduce the energy consumption and promote its efficient use, and to constantly reduce waste or ideally recycle it or convert it into energy.

FormaCare also promotes stakeholder dialogue, not only to increase awareness about the improvements that are made in the formaldehyde sector, but also to get feedback and relevant information from all different types of stakeholders.

Another focus of the industry’s responsible role is in increasing knowledge on formaldehyde by independent research based on sound science (Please see also Q12 -What is industry’s role in increasing our knowledge on formaldehyde? LINK).

The industry’s responsibilities also include the environment. Wood-based panels for example are environmentally beneficial. Plywood and composite panels (oriented strand board plus the range of fibreboards and particleboards) use renewable forest wood. Particleboard uses recycled wood alongside forest thinning and sawmill products, thus making an important contribution to the rational use and enhancement of our forest resources. In fact, 95% of the wood-based panels are made from re-using old wood. Committed to eco-efficiency, our production processes make use of old wood particles and sawmill waste and recycle them to make new, sustainable products.

Industry will also continue to do what it has always done: evaluate and adapt safety measures based on the latest scientific knowledge and data. Industry will continue to ensure that:

a) proper emissions and exposure prevention measures are implemented in daily manufacturing processes, b) products are in accordance with the current technical standards and do not pose a risk to human health.

14. What is IARC and what conclusion has it reached on formaldehyde?

The International Agency for Research on Cancer (IARC), an advisory body of the World Health Organisation (WHO), recently recommended reclassifying formaldehyde from group 2A -“probably carcinogenic to humans” to group 1 - “carcinogenic to humans”. This recommendation is not legally binding. In the preamble to monographs it is explicitly emphasised by IARC: “… no recommendation is given with regard to regulation or legislation…”.

IARC took its decision after reviewing available scientific information, at a meeting held from 2 to 9 June 2004 in Lyon, France. The reclassification is based on the increased risk of the very rare nasopharyngeal cancer observed in workers exposed to high levels of formaldehyde over 60 years ago. IARC also determined that the studies they reviewed were not considered sufficient to establish a clear causal association with other forms of cancer like leukaemia. The EU regulatory authorities, e.g. France who provided the dossier, consequently did not take up other forms of cancer, including leukaemia. The reason for that may be the lack of a plausible mechanism for systemic tumors like leukemia.

IARC reviewed in 2004 a number of epidemiological studies. These studies indicated that individuals exposed up to sixty years ago to high doses of formaldehyde showed an increased risk of the very rare nasopharyngeal cancer. Therefore, IARC recommended reclassifying formaldehyde from group 2A -“probably carcinogenic to humans” to group 1 - “carcinogenic to humans” .

IARC is mainly referring to the three largest so-called “cohort studies” on formaldehyde from 2003 and 2004. Only one of these three studies shows an elevated number of cancer cases in the nasopharyngeal area, and in this one study, only one of the ten observed manufacturing plants has shown an above-average accumulation of cases. Overall, 50 000 chemical workers have been observed who were in contact with formaldehyde at the workplace. Nine nasopharyngeal cancer cases have been registered – seven would have been statistically expected for a group of persons who is not in contact with formaldehyde. Ten more years of epidemiological data concerning the NCI (National Cancer Institute) study will become available 2007/2008. A detailed review of the disease cluster observed at this particular plant 1, the manufacturing plant in the US that alone is responsible for almost three fourths of the cases in the NCI study has recently been carried out. Thereby it was shown that exposures in silver smithing and metal industries might have been an important factor for development of this specific tumor type. In addition, a critique of the statistical methods used by NCI has been published concluding that some aspects of the statistical approach are to be challenged scientifically.

It is important to note that in the EU, formaldehyde is categorised as a category 3 carcinogen – “Limited evidence of carcinogenic effect”*. This is the current regulation today relevant for producers and users in the EU. The classification of IARC is a scientific evaluation and recommendation that has no legally binding implication in a strict sense. Nevertheless, it has to be expected that the EU will react to this recommendation.

Dangerous Substances Directive - category 3 (C3) carcinogen leading to a risk phrase R 40 (Limited evidence of a carcinogenic effect).