http://en.wikipedia.org/wiki/Formaldehyde
Formaldehyde solutions are applied topically in medicine to dry the skin, such as in the treatment of warts
Formaldehyde is highly toxic to all animals, regardless of method of intake. Ingestion of as little as 30 mL (1 oz.) of a solution containing 37% formaldehyde has been reported to cause death in an adult human.[29] Water solution of formaldehyde is very corrosive and its ingestion can cause severe injury to upper gastrointestinal tract.
Formaldehyde can be toxic, allergenic, and carcinogenic.[5] Because formaldehyde resins are used in many construction materials it is one of the more common indoor air pollutants.
Formaldehyde inhaled at this concentration may cause headaches, a burning sensation in the throat, and difficulty breathing, as well as triggering or aggravating asthma symptoms.
________________________________________ |
A 1988 Canadian study of houses with urea-formaldehyde foam insulation found that formaldehyde levels as low as 0.046 ppm were positively correlated with eye and nasal irritation.[34]
Although many studies have failed to show a relationship between formaldehyde and asthma, a recent review of studies has shown a strong association between exposure to formaldehyde and the development of childhood asthma.[35]
Chronic exposure at higher levels, starting at around 1.9 ppm, has been shown to result in significant damage to pulmonary function, resulting in reduced maximum mid-expiratory flow and forced vital capacity.[36]There is also research that supports the theory that formaldehyde exposure contributes to reproductive problems in women.
________________________________________ |
A study on Finnish women working in laboratories at least 3 days a week found a significant correlation between spontaneous abortion and formaldehyde exposure, and a study of Chinese women found abnormal menstrual cycles in 70% of the women occupationally exposed to formaldehyde compared to only 17% in the control group.[36] There have been no studies done on the effect of formaldehyde exposure on reproduction in men.
________________________________________ |
The primary exposure concern is for the workers in the industries producing or using formaldehyde. As far back as 1987, the U.S. EPA classified it as aprobable human carcinogen and after more studies the WHO International Agency for Research on Cancer (IARC), in 1995, also classified it as a probable human carcinogen.
Further information and evaluation of all known data led the IARC to reclassify formaldehyde as a known human carcinogen [37] associated with nasal sinus cancer and nasopharyngeal cancer.[38] Recent studies have also shown a positive correlation between exposure to formaldehyde and the development of leukemia, particularly myeloid leukemia.[39][40]
The formaldehyde theory of carcinogenesis was proposed in 1978. In the residential environment, formaldehyde exposure comes from a number of different routes; formaldehyde can off-gas from wood products, such as plywood or particle board, but it is produced by paints, varnishes, floor finishes, and cigarette smoking as well.[41]
________________________________________ |
For most people, irritation from formaldehyde is temporary and reversible, though formaldehyde can cause allergies and is part of the standard patch test series. People with formaldehyde allergy are advised to avoid formaldehyde releasers as well
Formaldehyde has been banned in cosmetics in both Sweden and Japan.
Formaldehyde levels in building environments are affected by a number of factors. These include the potency of formaldehyde-emitting products present, the ratio of the surface area of emitting materials to volume of space, environmental factors, product age, interactions with other materials, and ventilation condition.
Formaldehyde emits from a variety of construction materials, furnishings, and consumer products. The three products that emit the highest concentrations are medium density fiberboard, hardwood plywood, and particle board. Environmental factors such as temperature and relative humidity can elevate levels because formaldehyde has a high vapor pressure.
Formaldehyde levels from building materials are the highest when a building first opens because materials would have less time to off-gas. Formaldehyde levels decrease over time as the sources suppress.
________________________________________ |
Studies on the interactions between formaldehyde and proteins at the molecular level have been reported on the effects of the body’s carrier protein, bovine serum albumin. The binding of formaldehyde loosens the skeletal structure of BSA and exposure of aromatic ring amino acids in the internal hydrophobic region. Symptoms may affect personal awareness, making one feel tired or fatigue.[citation needed]
Formaldehyde inhalation has also shown to cause oxidative stress and inflammation in animals. Mice studied over an exposure to a high dose of formaldehyde (3ppm), showed increased levels of Nitric Oxide (NO−3) levels in plasma.
This result suggests that FA inhalation either decreased Nitric Oxide (NO) production or increased (Nitric Oxide) NO scavenging, which may be an anti-stress mechanism in the body. Formaldehyde inhalation changes the sensitivity of immune system, which influences oxidative stress.[citation needed
________________________________________ |
In June 2011, the twelfth edition of the National Toxicology Program (NTP) Report on Carcinogens (RoC) changed the listing status of formaldehyde from “reasonably anticipated to be a human carcinogen” to “known to be a human carcinogen”.[6][7][8]
Concurrently, a National Academy of Sciences (NAS) committee was convened and issued an independent review of the draft United States Environmental Protection Agency IRIS assessment of formaldehyde, providing a comprehensive health effects assessment and quantitative estimates of human risks of adverse effects.[51]
________________________________________ |
International bans
There are several web articles claiming that formaldehyde has been banned from manufacture or import into the European Union (EU) under REACH (Registration, Evaluation, Authorization, and restriction of Chemical substances) legislation.
???
This appears to be misinformation, as official EU chemical databases contradict these claims as of February 19, 2010. This misconception has gained some ground. Formaldehyde is not listed in the Annex I of Regulation (EC) No 689/2008 (export and import of dangerous chemicals regulation), nor on a priority list for risk assessment.
However, formaldehyde is banned from use in certain applications (preservatives for liquid-cooling and processing systems, slimicides, metalworking-fluid preservatives, and antifouling products) under the Biocidal Products Directive.[52][53] In the EU, the maximum allowed concentration of formaldehyde in finished products is 0.2%, and any product that exceeds .05% has to include a warning that the product contains formaldehyde.[46]
In the United States, a bill was passed in congress on July 7, 2010 regarding the use of formaldehyde in hardwood plywood, particle board, and medium density fiberboard. The bill limited the allowable amount of formaldehyde emissions from these wood products to .09 ppm, a standard which companies will have to meet by January, 2013.[54] Formaldehyde was declared a toxic substance by the 1999 Canadian Environmental Protection Act.[55]
________________________________________ |
FEMA trailer incidents
[edit]Hurricanes Katrina and Rita
In the U.S. the Federal Emergency Management Agency (FEMA) provided travel trailers, recreational park trailers and manufactured homes starting in 2006 for habitation by residents of the U.S. gulf coast displaced by Hurricane Katrina and Hurricane Rita. Some of the people who moved into the trailers complained of breathing difficulties, nosebleeds, and persistent headaches. Formaldehyde-catalyzed resins were used in the production of these homes.
The United States Centers For Disease Control and Prevention (CDC) performed indoor air quality testing for formaldehyde[56] in some of the units. On February 14, 2008 the CDC announced that potentially hazardous levels of formaldehyde were found in many of the travel trailers and manufactured homes provided by the agency.[57][58]
The CDC's preliminary evaluation of a scientifically established random sample of 519 travel trailers and manufactured homes tested between Dec. 21, 2007 and Jan. 23, 2008 (2+ years after manufacture) showed average levels of formaldehyde in all units of about 77 parts per billion (ppb). Long-term exposure to levels in this range can be linked to an increased risk of cancer and, at levels above this range, there can also be a risk of respiratory illness.
These levels are higher than expected in indoor air, where levels are commonly in the range of 10-20 ppb, and are higher than the Agency for Toxic Substance Disease Registry (ATSDR, division of the CDC) Minimal Risk Level (MRL) of 8 ppb.[59] Levels measured ranged from 3 ppb to 590 ppb.[60]
FEMA, which requested the testing by the CDC, said it would work aggressively to relocate all residents of the temporary housing as soon as possible. Lawsuits are being filed against FEMA as a result of the exposures.[61]
________________________________________ |
[edit]Iowa floods of 2008
Also in the U.S., problems arose in trailers again provided by FEMA to residents displaced by the Iowa floods of 2008. Several months after moving to the trailers, occupants reported violent coughing, headaches, as well as asthma, bronchitis, and other problems.
Tests showed that in some trailers, levels of formaldehyde exceeded the limits recommended by the U.S. Environmental Protection Agency and American Lung Association.[62][63] The associated publicity has resulted in additional testing to begin in November.[64]
________________________________________ |
[edit]2008 Sichuan earthquake
After an earthquake hit Sichuan, China, a large number of survivors were housed in trailers made with medium-density fiberboard that emitted up to 5 times China's maximum allowable formaldehyde levels. In April, 2009, there were 100 miscarriages recorded in this community, which may have been linked to exposure to high levels of formaldehyde found in the trailers used for housing after the disaster.[
________________________________________ |
Contaminant in food
Scandals have broken in both the 2005 Indonesia food scare and 2007 Vietnam food scare regarding the addition of formaldehyde to foods to extend shelf life. After a four-year absence, in 2011 Indonesian authorities have again found some foods with formaldehyde being sold in markets in a number of regions across the country. Besides using formaldehyde, they also use borax, but not combined together.[65]
In August 2011, at least at 2 Carrefour supermarkets, the CentralJakarta Livestock and Fishery Sub-Department found a sweet glutinous rice drink (cendol) contained 10 parts per million of formaldehyde.[66] Foods known to be contaminated include noodles, salted fish, tofu, and rumors of chicken and beer.
In some places, such as China, formaldehyde is still used illegally as a preservative in foods, which exposes people to formaldehyde ingestion.[67] In humans, the ingestion of formaldehyde has been shown to cause vomiting, abdominal pain, dizziness, and in extreme cases can cause death; in addition, there is limited evidence of a carcinogenic effect.[5][36] Testing for formaldehyde is by blood and/or urine by gas chromatography-mass spectrometry.
Other methods include infrared detection, gas detector tubes, etc., of which HPLC is the most sensitive [68] In the early 1900s, it was frequently added by US milk plants to milk bottles as a method of pasteurization due to the lack of knowledge regarding formaldehyde's toxicity.
In 2011 in Nakhon Ratchasima, Thailand, truckloads of rotten chicken were exposed to formaldehyde in which "a large network" including 11 slaughterhouses run by a gang were implicated.[69] In 2012, 1 billion Rupiah (almost 1 million USD) of fish were imported from Pakistan to Batam, Indonesia were found laced with formaldehyde.[70
________________________________________ |
http://en.wikipedia.org/wiki/Formaldehyde
|