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IAQ UK is an independent organisation with the aim of 'raising the agenda of indoor air quality within the home and workplace'

IAQUK Resources - Formaldhyde

History and Discovery


It was accidental produced by Alexander Mikhailovich Butlerov in 1859 during the incomplete combustion of carbon, as he was investigating the structures of organic compounds.  The Russian chemist is also known for producing the first artificial sugar. Incidentally he has a lunar impact crater name after him (Butlerov) on the moon to commemorate his contribution to chemistry.  Nine years after his discovery, eminent German Chemist August Wilhelm von Hofmann passed a mixture of methanol alcohol and air over a heated platinum spiral, producing Formaldehyde.   In the year of Hoffman’s death, 1892, Friedrich August Kekule von Stradonitz isolated pure Formaldehyde oxidation of methanol with air using a metal catalyst, which is still used as a method in manufacturing today. When many people think of Formaldehyde, the first thing that comes to mind is embalming, which is one of the first mass industry uses.  However, one could argue that Formaldehyde has a place in the Hellenistic realms of Cleopatra and her desire for the preservation of beauty and youth, with controversially one possible explanation of her death by a toxic ointment applied to her skin, fatally poisoning her.  Formaldehyde uses were initially primarily within medicine, preventing the spread of cholera in food and water, Formaldehyde was used within the food preservation. Formaldehyde was also used with lime to dust districts in America that had encumbered the bubonic plague. Formaldehyde has been used in various vaccinations, including polio, diphtheria, hepatitis A, influenza and Japanese encephalitis vaccine. Although the food and medical industries experimented with Formaldehyde, it was the plastic industry that contributed towards the popularity of the compound.

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Formaldehyde is probably one of the most common volatile organic compounds (VOC), in the workplace and home, it is practically everywhere in our environment.  It is also known as Methyl Aldehyde, Methylene Oxide, Oxymethylene and Oxomethane.

 

Formaldehyde is a simple compound consisting of ydrogen, xygen and carbon.  It is a naturally occurring substance in the environment, but since the discovery and industrial processing of Formaldehyde it has become one of the most common indoor air pollutants.


Formaldehyde is a natural part of our environment; it is formed in nature as a result of photochemical processes from the oxidation of methane in the atmosphere. The interaction of oxygen and methane with the sun breaks down molecules to carbon dioxide.  Plants and animals produce Formaldehyde via decomposing of organic matters.  It can be processed as a by-product of a process, for instance cooking brussel sprouts orcabbage produces Formaldehyde.

 

Formaldehyde is naturally produced in very small amounts in our bodies (about 2.5μ of Formaldehyde per ml of blood) as a part of our normal, everyday metabolism and causes us no harm. Formaldehyde is required for the synthesis of DNA and amino acids (the building blocks of protein).

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Health Effects


Formaldehyde typically enters the body via inhalation, although Formaldehyde can also be ingested and absorbed through the skin. Because Formaldehyde can be dissolved easily in water, the compound does not build up in our bodies.  It is quickly absorbed, broken down and either excreted in our urineor breathed out as carbon dioxide.  Yet, despite our bodies’ ability to remove Formaldehyde, the compound has been discussed as a cause of DNA and protein cell damage.  Further studies are exploring the correlation between Formaldehyde and long term health effects, including cancer. However there are conflicting cohort studies to exploring the relationship.  The Environmental Protection Agency (EPA) classified Formaldehyde as a probable human carcinogen under conditions of unusually high or prolonged exposure.

 

Short term health effects often initially display as irritation to the nose, throat and eyes. Depending on the duration and concentration of exposure, the eyes can become red and sore, sometimes resulting in eye watering and blurred vision. The nose and throat irritation can lead to sneezing, coughing and nasal discharge. Occupants may describe tingling, orsoreness to their throats and noses. Individuals may also complain of headachesor feeling of nausea, even breathlessness has been associated.

 

Long term exposure can cause a decrease of the lung function capacity, which may effect asthmatics, although there is no conclusive evidence to confirm.  It can also lead to pulmonary oedema, which is an accumulation of fluids in the lungs.  Because formaldehyde is a hardening agent, it can cause similar effects to the skin; it can also induce swelling and contribute to dermatitis and allergic eczema. 

 

Formaldehyde is a sensitising agent to the skin and respiratory system.  Therefore even small exposure can trigger an allergic reaction.  Menstrual and thyroid irregularities, impairing cognitive functions including memory and concentration and contributing to sleep disturbances have been recognised as potential symptoms.

 

There have been considerable research to investigate the potential health effects of exposure to Formaldehyde, ranging from irritation at lower levels to serious health consequences.  It is worth noting that individuals will respond differently to exposure and where some people may report moderate discomfort, others may respond with no symptoms even when exposure to the same concentrations.  Other respiratory tract toxicants, such as acrolein, acetaldehyde, crotonaldehyde, furfural, glutaraldehyde and ozone, may lead to additional synergistic effects. Existing health (asthma) and lifestyle habits such as smoking, which contains high concentrates of Formaldehyde, will also influence exposure responses.

Technical - Formaldhyde - H2CO


  • 1 carbon atoms bonded with 2 hydrogen atoms and covalently bonded to 1 oxygen atom
  • Colourless gas
  • Pungent odour
  • CAS Number: 50-00-0
  • LTEL - 2ppm (2.5 mg/m³)
  • STEL - 2ppm (2.5 mg/m³)
  • Risk Phrases R23/24/25, 34, 40, 43
  • Safety Phrases S1/2, 26, 36/37, 39, 45, 51

Effective Control Measures

 

  • The type of control measures adopted would depend on the source of contamination.  
  • Formaldehyde sourced by a product or activity should be risk assessed, as per the Control of Substances Hazardous to Health Regulations and supplementary EH40 occupational exposure limits.
  • The COSHH hierarchy of control measures to be adopted, with elimination being the most appropriate measure.  Source alternative products/processes that do not contain Formaldehyde. 
  • Provide personal protective equipment where required, according to the exposure limits.  PPE should not be used as a substitute for removing the hazards at source. 
  • Conduct air monitoring to determine levels and ensure maximum exposure limits are not exceeded. 
  • Monitor ventilation to prevent concentration accumulation. 
  • The introduction of health surveillance for those individuals exposed to concentrations of 2.0 PPM and above. 
  • Review fittings and furnishing and adopt low gas or zero gas compressed wood boards, resins, glues, adhesives, paints and even consider pool cars and VOC emissions. 
  • Introduce training and consultation for all employees exposed to Formaldehyde concentrations of 0.1 PPM or greater. The training will raise the employees' awareness of specific hazards in their workplace and of the control measures employed. It will also contribute to medical surveillance whereby employees will be able to identify signs or symptoms related to the health effects of Formaldehyde.

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Sampling Strategy

 

If sampling may be required, a sampling strategy is important to identify the type of monitoring required and the identification of pollutant sources.

 

Identify the need for sampling

 

Where Formaldehyde is is being used that it may be released into the workplace atmosphere or contaminate the skin. This information would be available via manufacturer’s data sheets and a COSHH assessment (Control of Substances Hazardous to Health).

 

Any activities that involve that involve heating resins that contain Formaldehyde, cutting, grinding, sanding materials that generate Formaldehyde dusts, sprays or liquids, such preservatives or disinfecting, will require investigating. Identifications such as health complaints or symptoms indicative of exposure to Formaldehyde, complaints about odours within the environment would require further examination.  New furnishings and products that have been introduced into the environment, decorating (painting) that may release VOCs, combined with low ventilation rates, high humidity/temperatures that extenuate vapour release and allow accumulation of vapours.

 

Methodology

 

For a systematic approach the following consideration as part of the methodology for sampling would be recommended:

 

  • Selection of correct sampling method and analysing of data
  • Location of exposed individuals
  • Source of pollutant
  • Number of samples required
  • Location and method of sampling
  • Review
  • Changes in the environment, person or activity may influence the samples, such as:
  • Changes in ventilation, temperature and humidity, which may be of a result from internal mechanical alterations, or from seasonal weather changes
  • Changes in the process or work habits of an individual
  • Occupational standards

 

Workplace Exposure Limits (WEL) is provided by EH40/2005

Long Term Exposure Limits (LTEL)

(8 hour reference period)

2 ppm (2.5 mg m-3)

 

Short Term Exposure Limits (STEL)

(15 minute reference period)

2 ppm (2.5 mg m-3)

 

Although EH40 applies a maximum workplace exposure limit, the COSHH Regulations place a duty to ensure exposure is reduced as low as is reasonable practicable to hazardous substances.  Therefore considering adopting a lower exposure level and implement control measure below the EH40 standards, such as 0.1 PPM which is the Swedish indoor standard.

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Sources of Pollution


Formaldehyde is an ingredient in hundreds of products we use every day, in our surroundings and generated as a by-product.  The versatility of the organic compound is useful as a building block for other, more complex chemicals.   One of the first consumer items, was the production of buttons, Galalith Gesellschaft Hoff and Company compounded Formaldehyde and fat-free milk curd to formulate casein-formaldehyde, a new synthetic plastic. By the early 20th century Formaldehyde was used to produce an array of resin plastic products.    By the end of the 20th century, Formaldehyde resins were used extensively in furniture and furnishings, primarily where pressed wood products used adhesives that contain urea-formaldehyde (UF) resins creating panel boards and fibre boards.  The wood treatment orpaint also contains Formaldehyde.   Formaldehyde-based glues help paint adhere to surfaces and veneer and paper overlays to particleboard.  As a preservation and anti-bacterial agent present in many cosmetics, including shampoo, deodorant, toothpaste, make up, soap, mouthwash, tanning agents, air fresheners and anti-aging cream as a few examples. It is used as a treatment for athlete's foot, spermaticide creams, found in cough drops, skin disinfectants,  It can be found in other consumable items such as paper towels, photographic paper and printing inks, newspapers, magazines. In textiles, Formaldehyde-based materials help bind dyes and pigments to fabrics, preventing colour run when washed.  It is also being used to prevent fabrics from wrinkling as it alters the textile fibres.   In veterinary medicine, it is used as an antiseptic and fumigant treatment, argiculturary it is used in seed treatment, insecticides and fungicides.   It is a component of glues and adhesives, paints, waterproof and greaseproof products, corrosion inhibitator and a stabiliser in petrol.  Formaldehyde can also be produced as a by product from processes such as smoking, wood burning stoves, kerosene heaters and other fuel-burning appliances.

 

Can we live without Formaldehyde?

 

Essentially the versatility of the Formaldehyde compound has contributed extensively to the advancement in technology of products and goods we surround our lives with.  This is why it has become one of the most prevalent pollutants within our indoor environments.

Formaldehyde Concentrations

 

 

Health Effects

 

0.03 PPM

 

None reported

0.03 - 1.0 PPM

 

Odour Threshold:

0.03 PPM – 10% of the population detect odour

0.18 PPM – 50% of the population detect odour

0.60 PPM – 90% of the population detect odour

 

 

PPM

 

Eye irritation if exposure occurs with other pollutants

 

- 2.0 PPM

 

Eye irritation

 

– 25 PPM

 

 

Upper airway irritation/increased nasal airway resistance

0.1–3.1 PPM - Throat and nose irritation threshold exposure

0.5–2.0 PPM - Decreased nasal mucus flow rate

2.5–3.7  PPM - Biting sensation in eyes and nose

 

 

5 – 30 PPM

 

Lower airway and chronic pulmonary obstruction

 

50 – 100 PPM

 

Pulmonary edema, inflammation, pneumonia

 

100+ PPM

 

Death

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Monitoring

 

Identification

 

The most obvious method is via smell, which is often described as strong and pungent.  Our ability to smell odours are between 0.05 – 1.00 PPM. Individuals that are more sensitive to Formaldehyde may react to lower exposure concentrations. Introducing new furniture or furnishing, recently decorated and/or introducing new products into the workplace may be a potential source of Formaldehyde. Although Formaldehyde can continue releasing vapours for months even years after being integrated into an environment.  As an volatile organic compound (VOC), Formaldehyde vaporises at room temperature. Conditions such as high humidity and temperatures can increase the rate of release from Formaldehyde.  If Formaldehyde is combined with water to create a non-volatile compound, it can be absorbed back into surfaces, such as wood and textiles.

 

Monitoring

 

Museums that use Formaldehyde for preservation of animal species have employed the use of a lead strip within the display cabinet to test high levels of Formaldehyde.  The lead strip reacts to the pollutant environment and over a period of time will corrode developing a grey-white efflorescence appearance.  Although this information cannot quantify concentrates of even directly confirm the cause was H2CO, but merely used as a method to identify polluted environments.   

Technology advances have enabled practitioners to more accurately sample.   There are several methods for sampling, including passive, detection tubes and photo-ionization detectors.

 

Passive Sampling

 

Passive sampling can implemented via monitoring dosimeter badges or identification strips.  Usually used for high level dosing when working or exposed to H2CO.  It is an inexpensive method which can also provide analyse for personal dosing and monitoring.  Passive sampling provides concentrations in the ambient air over a time period (days, weeks, months).  A strip or badge will contain an absorbent chemically impregnated paper which reacts to Formaldehyde.  The sample is analysed by an accredited labatory using chromotropic acid assay (CTA) analysis. Caution is applied to the accuracy of such testing methods, as complications such as incorrect storage, exposure to temperature and humidity can exposed reduce the capacity of the sampler significantly.

 

Gas detection Tubes

 

Gas detection tubes using the method of gas diffusion and colourmetric reaction. They can be used to measure time-weight averages (TWA) or provide an immediate on-the-spot analyse.  A glass tube with calibrated scales printed on the side will enable the practitioner to access concentrations of Formaldehyde efficiently.  As the detection agent within the tube becomes exposed to the vapour, the agent will turn a different colour.  The detection tubes provide quantitative results with a high degree of accuracy and selectivity.

 

Photo-Ionization Detector (PID)

 

A photo-ionization detector (PID) can provide direct reading of Total Volatile Organic Compounds (TVOC).  The detector identifies TVOCs by using an ultraviolet (UV) lamp that charges the compounds molecules into positive ions which is then detected on a metal screen. After the charged molecules pass through the detector, they then reform back to their original status.  The PID is an efficient and inexpensive method for monitoring, that provides instant readings and monitoring continuously, which is useful when identifying source locations and routes of pollution.

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