Formaldehyde
Formaldehyde is a naturally-occurring organic compound with the chemical formula CH2O. It is the simplest aldehyde and is also known by its systematic name methanal. [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][1]
In pure form, formaldehyde is a gas but is often used in liquid form after diluting with water. It is a colourless highly flammable liquid or gas with a pungent odour that is detectable at 1 part per million (ppm). Formaldehyde mixes with water, acetone, benzene, diethyl ether, chloroform and ethanol. It reacts with strong oxidisers, alkalis and acids, phenols and urea. Poisonous gases are produced if formaldehyde catches fire. It is very reactive, combines with many substances and polymerises easily. [2]
In view of its widespread use, toxicity and volatility, exposure to formaldehyde is a significant consideration for human health. In 2011, the United States National Toxicology Program described formaldehyde as “known to be a human carcinogen”. [1]
Uses [3]
Water-based solutions containing dissolved formaldehyde, known as ‘formalin’, are used in:
- forensic/hospital mortuaries and pathology laboratories
- funeral (embalming) industry
- resins manufacture
- leather and fur tanning
- photographic film processing
- sanitising treatments
- lubricants
- analytical laboratories
- fumigation
Resins manufactured with formalin are used in:
- pressed wood manufacture
- paper and textile treatments
- fibreglass industry
- foam insulation
- foundry industry
- firelighter manufacture
- anti-graffiti wall sealer
The major use of formalin is in adhesives used in the manufacture of resins used to make pressed wood products, particularly particleboard and medium-density fibreboard.
Another major use is in medicine-related laboratories where it is used to fix tissues and organs, and in the funeral industry, in embalming processes, where it functions as a disinfectant and preservative.
Formaldehyde is also present at low concentrations as a preservative in a range of personal care and consumer products including hair straightening treatments.
Formaldehyde is naturally produced during burning of organic matter and by a variety of natural biological and chemical processes. It is found in cigarette smoke, and is emitted from cooking and heating appliances such as gas stoves and heaters.
Sources of Emission & Routes of Exposure [2]
Sources of Emission
- Industry sources: The major industrial sources include manufacturing plants that produce or use formaldehyde, or substances that contain formaldehyde. Mining, wood and paper industries and electricity supply are those that produce the most formaldehyde. Catalytic cracking, coking operations and fuel combustion sources such as boilers, furnaces and engines in manufacturing processes also generate formaldehyde. Formaldehyde is present in urea-formaldehyde and phenol-formaldehyde resins and copper plating solutions.
- Diffuse sources: Formaldehyde is released from burning fuel in homes, and is in products such as carpets and pressed wood products. It is directly emitted into the atmosphere and can also be formed in the atmosphere as a result of the photochemical oxidation of reactive organic gases in polluted atmospheres containing ozone and nitrogen oxides.
- Natural sources: Formaldehyde can form as a result of forest fires, and is also present in animal wastes and the microbial products of biological systems. It can also be formed in seawater by photochemical processes.
- Transport sources: Vehicle exhaust is a major source of formaldehyde.
- Consumer products: Formaldehyde may be present in glues, fibreboard, particle board, furniture, textiles and some insulation. Formaldehyde-based resins are used in pressed wood, permanent press fabrics (clothing, manchester, draperies), wallpaper, paint, grocery bags and waxed paper. Detergents, cosmetics and other domestic chemicals (shampoos, hair conditioners and bubble baths) contain formaldehyde as an antimicrobial agent. Cigarettes, cigars and other tobacco products also contain formaldehyde.
Routes of Exposure
Formaldehyde can enter the body by inhaling fumes (from smog, cigarettes and other tobacco products, gas cookers and open fireplaces), contact with solutions containing formaldehyde, or by eating and drinking foods containing formaldehyde. Eating formaldehyde-tainted foods may have a different effect than inhaling formaldehyde vapours.
Health Effects [4]
Acute Effects
- The major toxic effects caused by acute formaldehyde exposure via inhalation are eye, nose, and throat irritation and effects on the nasal cavity. Other effects seen from exposure to high levels of formaldehyde in humans are coughing, wheezing, chest pains, and bronchitis.
- Ingestion exposure to formaldehyde in humans has resulted in corrosion of the gastrointestinal tract and inflammation and ulceration of the mouth, oesophagus, and stomach.
- Acute animal tests in rats and rabbits have shown formaldehyde to have high acute toxicity from inhalation, oral, and dermal exposure.
Chronic Effects
- Chronic exposure to formaldehyde by inhalation in humans has been associated with respiratory symptoms and eye, nose, and throat irritation.
- Repeated contact with liquid solutions of formaldehyde has resulted in skin irritation and allergic contact dermatitis in humans.
- Animal studies have reported effects on the nasal respiratory epithelium and lesions in the respiratory system from chronic inhalation exposure to formaldehyde.
- The Reference Dose (RfD) for formaldehyde is 0.2 milligrams per kilogram body weight per day (mg/kg/d) based on a decrease in body weight gain and effects on the stomach in rats.
- EPA has not established a Reference Concentration (RfC) for formaldehyde.
- The Agency for Toxic Substances and Disease Registry (ATSDR) has established a chronic inhalation minimal risk level (MRL) of 0.003 ppm (0.004 milligrams per cubic meter, mg/m3) based on respiratory effects in humans.
Reproductive/Developmental Effects
- An increased incidence of menstrual disorders were observed in female workers using urea-formaldehyde resins. However, possible confounding factors were not evaluated in this study.
- A study of hospital equipment sterilising workers did not report an association between formaldehyde exposure and increased spontaneous abortions.
- Developmental effects, such as birth defects, have not been observed in animal studies with formaldehyde.
Cancer Risk
- Occupational studies have noted statistically significant associations between exposure to formaldehyde and increased incidence of lung and nasopharyngeal cancer. This evidence is considered to be “limited,” rather than “sufficient,” due to possible exposure to other agents that may have contributed to the excess cancers.
- Animal studies have reported an increased incidence of nasal squamous cell carcinomas by inhalation exposure.
- EPA considers formaldehyde to be a probable human carcinogen (cancer-causing agent) and has ranked it in EPA’s Group B1.
Safety [5]
First Aid Measures
- Eye Contact: Check for and remove any contact lenses. Immediately flush eyes with running water for at least 15 minutes, keeping eyelids open. Cold water may be used. Get medical attention immediately.
- Skin Contact: In case of contact, immediately flush skin with plenty of water. Cover the irritated skin with an emollient. Remove contaminated clothing and shoes. Cold water may be used. Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention.
- Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek immediate medical attention.
- Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention immediately.
- Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-to-mouth resuscitation. WARNING: It may be hazardous to the person providing aid to give mouth-to-mouth resuscitation when the inhaled material is toxic, infectious or corrosive. Seek immediate medical attention.
- Ingestion: If swallowed, do not induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. Loosen tight clothing such as a collar, tie, belt or waistband. Get medical attention immediately.
Fire & Explosion Information
- Formaldehyde is flammable.
- Auto-Ignition Temperature is 430°C (806°F)
- Products of Combustion include carbon oxides (CO, CO2).
- Formaldehyde is flammable in presence of open flames and sparks, of heat. Non-flammable in presence of shocks, of oxidising materials, of reducing materials, of combustible materials, of organic materials, of metals, of acids, of alkalis.
- Formaldehyde is non-explosive in presence of open flames and sparks, of shocks.
- To extinguish small fires use dry chemical powder.
- To extinguish large fires, use alcohol foam, water spray or fog. Cool containing vessels with water jet in order to prevent pressure build-up, auto-ignition or explosion.
- Formaldehyde is explosive in the form of vapour when exposed to heat or flame.
- Vapour may travel considerable distance to source of ignition and flash back.
- When heated to decomposition, it emits acrid smoke and irritating fumes.
- CAUTION: MAY BURN WITH NEAR INVISIBLE FLAME
Exposure Controls & Personal Protection
Engineering Controls
- Provide exhaust ventilation or other engineering controls to keep the airborne concentrations of vapours below their respective threshold limit value.
- Ensure that eyewash stations and safety showers are proximal to the work-station location.
Personal Protective Equipment
The following personal protective equipment is recommended when handling formaldehyde:
- Safety glasses;
- Lab coat;
- Vapour respirator (be sure to use an approved/certified respirator or equivalent);
- Gloves (impervious).
Personal Protection in Case of a Large Spill:
- Splash goggles;
- Full suit;
- Vapour respirator;
- Boots;
- Gloves;
- A self contained breathing apparatus should be used to avoid inhalation of the product.
- Suggested protective clothing might not be sufficient; consult a specialist BEFORE handling this product.
Regulation
United States [6,7]
|
|
|
|
|
OSHA PEL -General Industry |
0.75 ppm TWA |
HE1 — cancer(lung, nasopharynx, oropharynx, nasal passages) |
|
HE9 –bronchial asthma |
||
|
HE11 –pulmonary oedema, pneumonia |
||
|
HE14 — eye,skin, and respiratory irritation; allergic contact dermatitis |
||
|
OSHA PEL – Construction Industry |
0.75 ppm TWA |
HE1 — cancer(lung, nasopharynx, oropharynx, nasal passages) |
|
HE9 –bronchial asthma |
||
|
HE11 –pulmonary oedema, pneumonia |
||
|
HE14 — eye,skin, and respiratory irritation; allergic contact dermatitis |
||
|
OSHA PEL – Shipyard Employment |
0.75 ppm TWA |
HE1 — cancer(lung, nasopharynx, oropharynx, nasal passages) |
|
HE9 –bronchial asthma |
||
|
HE11 –pulmonary oedema, pneumonia |
||
|
HE14 — eye,skin, and respiratory irritation; allergic contact dermatitis |
||
|
NIOSH REL |
0.016 ppm TWA 0.1 ppm Ceiling(15 minutes) |
HE4 –headache, sensation of pressure in head, and heart palpitations;gastrointestinal irritation and vomiting; convulsions, coma |
|
HE9–respiratory sensitisation |
||
|
HE11 –bronchitis, pulmonary oedema, pneumonitis, pneumonia, and respiratory failure |
||
|
HE14 –respiratory irritation and symptoms; eye irritation and burns, with visionloss; dermatitis |
||
|
ACGIH TLV? |
0.1 ppm TWA |
HE15 — upperrespiratory and eye irritation |
|
|
0.75 ppm TWA |
Australia [8]
Safe Work Australia: Safe Work Australia has established a time weighted average (TWA) concentration for formaldehyde of 1ppm or 1.2mg/m3. The Short term exposure limit (15mins) is 2ppm or 2.5mg/m3.
The advisory carcinogen category is 2.
References
http://en.wikipedia.org/wiki/Formaldehyde
http://www.npi.gov.au/resource/formaldehyde-methyl-aldehyde
http://www.nicnas.gov.au/communications/publications/information-sheets/existing-chemical-info-sheets/formaldehyde-factsheet
http://www.epa.gov/ttn/atw/hlthef/formalde.html
http://www.sciencelab.com/msds.php?msdsId=9924095
http://www.cdc.gov/niosh/npg/npgd0293.html
http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=219&tid=39
http://www.safeworkaustralia.gov.au/sites/SWA/about/Publications/Documents/772/Workplace-exposure-standards-airborne-contaminants.pdf
[/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]