Formaldehyde甲醛 is an organic compound with
the formula CH2O. It is the simplest form of aldehyde, hence its
systematic name methanal.
A
gas at room temperature, formaldehyde is colorless and has a characteristic
pungent, irritating odor. Commercial
solutions of formaldehyde in water, commonly called formalin, were formerly
used as disinfectants and for preservation of biological specimens.
In
view of its widespread use, toxicity and volatility, exposure to formaldehyde
is a significant consideration for human health.
Uses
Formaldehyde
is used in photography, paints, explosives,
as adhesive in making fiberboards,
in textile industry to make fabrics
crease-resistant, wet-strengthening for sanitary
paper products, automobiles components,
to make into foam for insulation, etc
It
is also used as disinfectant in medical
apparatus, for treatment for skin diseases, as
treatment for parasites in aquarium, and in cosmetics and personal hygiene products
to prevent bacterial growth.
Perhaps
the most well known usage of formaldehyde is for preservation
of human and animal tissues, and as a fixative for microscopy in histology.
International bans
In
the EU, formaldehyde is banned from use in preservatives for liquide-cooling
and processing systems, slimicides, metalworking-fuild preservatives, and antifouling
products, under the Biocidal Product Directive.
The maximum allowed concentration of formaldehyde in finished products
is 0.2%, and any product that exceeds 0.05% has to include a warning that the
product contains formaldehyde.
In
the United States, the allowable amount of formaldehyde emissions from these
wood products to 0.09 ppm, in 2010 Formaldehyde Standards for Composite Wood
Products Act.
In
Canada, formaldehyde was declared a toxic substance by the 1999 Environmental
Protection Act.
Contaminant in food
In
the early 1900s, formaldehyde was added in fresh milk as a method of
pasteurization.
In
2005, in Jakarta, Indonesia, the Indonesian government found that 60% of noodle
shops in Jakarta had been serving noodles
laced with formaldehyde.
In
2007, in Vietnam, formaldehyde was found in noodles of the national dish, Phở. The food scares also involved dangerous
banned pesticides in fruit and vegetable, and carcinogen in soy sauce.
In
2010, 2 Carefour hypermarkets in Jakarta were found to had sold cendol
contained 10 ppm of formaldehyde.
In
2011, in Nokhon Rachasima, Thailand, a sizeable quantities of rotten chicken treated with formalin were discovered.
In
2012, some 25 tonnes of mackerel fish worth 1
billion Rupiah ( @ 1 million USD ) imported from Pakistan to
Batam, Indonesia were found laced with formaldehyde.
Health Effects
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.
Formaldehyde
inhaled may cause headaches, a burning sensation in the throat, difficulty
breathing, and asthmatic symptoms.