Technically, formaldehyde can be defined as a volatile organic compound that is gaseous at room temperature. This gas is colorless, but has a strong and pungent odor. Formaldehyde is available in many forms, like formalin―a solution of formaldehyde, water, and methanol. Another is paraformaldehyde―a crystallized polymer of formaldehyde.
Natural and Man-made Sources of Formaldehyde
Formaldehyde is composed of carbon, hydrogen, and oxygen, and is found naturally in the atmosphere. It is produced in the atmosphere during forest fires. Apart from that, animal wastes and plant volatiles are also among the common sources of formaldehyde. Even animals and humans produce a small amount of formaldehyde in their body, during metabolism. But it is excreted so fast that there are no chances for this chemical compound to accumulate in the body. Fruits and vegetables, like apple, banana, cauliflower, pear, mushroom, etc., do contain formaldehyde in different levels. Seafood, especially crustaceans and Bombay ducks release formaldehyde, once they die. This is the reason why formaldehyde accumulates in their body, during cold storage. In such cases, it is advisable to soak and wash the food items thoroughly, before use.
Nowadays, the most common sources of formaldehyde are automobile exhaust and industrial emissions. Cigarette smoke too contains some amount of this chemical. Materials, like particleboard, paints and varnishes, certain cosmetics, carpets, disinfectants, etc., are also among the man-made sources of formaldehyde. Formaldehyde exposure is found to be considerably high in industries that produce plastics and resins, garments, furniture, wooden floors, etc. Formaldehyde is commercially prepared by the catalytic oxidation of methanol. Atmospheric formaldehyde is broken down within sometime, due to the action of sunlight and/or bacteria.
Formaldehyde in Our Daily Life
Formaldehyde is one of the most widely used organic compounds, and is an indispensable chemical in many industries. This compound is used for making pressed wood products, such as particle board, plywood, and fiberboard. Other such products include plastics, dyes, paint, paper products, glues and adhesives, disinfectants, cosmetics, shampoos, hair conditioners, pharmaceutical products, air fresheners, household antiseptics, carpet cleaners, and mouthwash. The list of household products with formaldehyde would be unending. According to recent studies, formaldehyde is present in both indoor and outdoor air in small amounts. Most of the materials with formaldehyde content release formaldehyde gas into the atmosphere.
In case of indoor air, formaldehyde sources include pressed wood products, gas stoves, cosmetics, and detergents. Whereas, one of the most important sources of outdoor formaldehyde content is automobile emissions. People working in industries that use formaldehyde in large amounts, like health care professionals and laboratory technicians, are more exposed to this chemical.
Formaldehyde Exposure Side Effects
Formaldehyde can enter the body through inhalation, ingestion, or skin absorption. While ingestion is not so common (barring accidents), the other two are the main causes of formaldehyde exposure. The nature and severity of the side effects depend on the concentration of formaldehyde, duration of exposure, and sensitivity level of the individual.
Ingestion: The most common symptom is irritation of the mouth, throat, and stomach. Other symptoms include severe stomach pain, loss of consciousness, nausea, vomiting, bleeding, etc. In high concentration, the chemical can cause severe damage to the upper gastrointestinal tract. It is said that ingestion of 20-30 ml of a solution with 37% formaldehyde concentration is sufficient to cause coma and death of a person.
Inhalation: Even though the symptoms of formaldehyde inhalation may vary from one person to another, in general, it can be categorized as follows. If the level of formaldehyde is between 0.1 to 5 ppm, inhalation may cause irritation of the eyes, nose, skin, and respiratory tract. If the level is between 5 to 20 ppm, it may cause breathing trouble, cough, and burning of the eyes and skin. In case of high formaldehyde levels, i.e. 20 to 100 ppm, severe symptoms like irregular heartbeat, chest pain, lung irritation, pulmonary edema, and even death may occur. It is also suggested that long-term exposure may lead to allergic asthma and hypersensitivity pneumonitis.
Skin and Eye Contact: If the eyes get exposed to formaldehyde solution directly, then the cornea may suffer severe damage that may lead to blindness. In case of exposure to formaldehyde gas or vapor, the eyes may turn red, along with a burning sensation and tear production. Exposure of the skin to formaldehyde can cause symptoms, like drying, cracking, itching, and scaling. Severe symptoms include pain, redness, burns, blisters, and scarring. Eczema, allergic dermatitis, etc., may also develop.
In short, the harmful effects of formaldehyde exposure can range from mild to life-threatening ones. As formaldehyde is found to be more reactive with moist body tissues, skin, eyes, and upper respiratory tract are found to be the most vulnerable areas. Formaldehyde side effects can vary from one person to another. While low levels of this gas in the air may trigger side effects in sensitive people, it may not affect others. Kids are found to be more sensitive, and are prone to develop severe symptoms, even if the concentration of formaldehyde is very low. Though formaldehyde exposure during pregnancy is linked to birth defects, there is insufficient evidence to prove the same.
Duration of Exposure: The harmful effects of formaldehyde exposure may vary on the basis of the period of exposure. It can either be an exposure for a brief period or a regular and long-term one, as in case of some industrial workers. Regular exposure is said to cause long-term health issues. In case of regular exposure that is considered chronic, the person may develop lesions inside the lungs, which may lead to lung damage. If a person with formaldehyde allergy comes into contact with this chemical, he/she may develop severe skin rash, which may end up in cracked, dry skin. If left untreated, scarring is also possible. The severity of the symptoms of this allergy may vary from one person to another. However, immediate treatment is recommended in such cases. It is also speculated that regular exposure may cause some types of cancer, especially, nasopharyngeal ones. In fact, the International Agency for Research on Cancer (IARC) has concluded that formaldehyde is carcinogenic for humans. Various other agencies have also listed the chemical as a human carcinogen. Formaldehyde exposure for a very short period can also give rise to symptoms that may range from mild to severe, as per the concentration of the chemical.
A formaldehyde level of less than 0.01 ppm is not known to cause any side effects, above 0.1 ppm, the chemical can cause symptoms, like burning sensation, runny nose, headaches, etc. The nature and severity of the symptoms will aggravate with the increasing levels of formaldehyde in the air. It has been found that the indoor level of formaldehyde has come down drastically after the 1982 ban on urea-formaldehyde foam insulation (UFFI). According to the United States Environmental Protection Agency (EPA), the average concentration of formaldehyde in older homes without UFFI is below 0.1 ppm, and in newer ones with more pressed wood articles, the level could be around 0.3 ppm. According to the federal standard set by the United States Occupational Safety and Health Administration (OSHA), the permissible exposure limit (PEL) for formaldehyde in the workplace is 0.75 ppm measured as an 8-hour time-weighted average (TWA).
How to Reduce Indoor Formaldehyde Level
- Minimize use of those materials that are sources of formaldehyde. They include pressed wood products (especially those with UF resin), paints, varnishes, permanent press clothing, cosmetics like nail polish, etc.
- Even the smoke from fireplaces and gas stoves contain this chemical, which can cause health problems, in case of long-term exposure. So, maintain fireplaces and wood stoves in good working condition and clean the chimneys at regular intervals.
- It is better to buy solid wood products, rather than those made of pressed wood.
- Adequate ventilation is also recommended, especially during painting, varnishing, installation of wallpaper, etc.
- Using an indoor air purifier may also prove beneficial.
- Avoid smoking cigarettes and other tobacco products inside the home.
- Houseplants like heart leaf philodendron, azalea, golden pothos, corn plant, and chrysanthemum may prove effective in removing formaldehyde from indoor air.
In short, formaldehyde is a chemical that is found in both indoor and outdoor air. Regular and long-term exposure to this chemical may cause certain health issues ranging from mild to severe. The duration of exposure, formaldehyde concentration, and sensitivity of the individual, are some of the factors that play a key role in determining the nature and severity of the symptoms. As formaldehyde is listed as a human carcinogen, avoid or minimize exposure to this chemical. In case of a minor exposure to formaldehyde solution, remove the clothing and wash the skin, hair, and eyes with water for a few minutes. In case of ingestion, drink four to eight ounces of water, if possible. In both cases, seek immediate medical attention. As there is no antidote for this chemical, treatment mainly involves decontamination, supplemental oxygen administration, and hemodialysis. Those who have suffered a major exposure, must be provided with medical treatment, at the earliest.