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DESIGNATIONS
CAS No.: 50-00-0
Registry names: Formaldehyde
Chemical name: Methanal
Synonyms, Trade names: Formic acid aldehyde, formalin, methyl aldehyde, oxomethane, methyleneoxide, oxymethylene, formyl hydrate, Formol, Fannoform, BFV, Formalith, Ivalon, Lysoform, Morbicid, Superslysoform, Tannosynt, Antverruc, Sandovac, Vobaderin
Chemical name (German): Formaldehyd, Methanal
Chemical name (French): Formaldéhyde, Méthanal
Appearance: colourless gas with pungent odour
Note: Commercially available aqueous solutions contain 35-55% formaldehyde. As formaldehyde has a tendency towards polymerisation, these solutions are stabilised with methanol (The addition of methanol increases the flammability).
BASIC CHEMICAL AND PHYSICAL DATA
| Empirical formula: | CH2O | |
| Rel. molecular mass: | 30.03 g | |
| Density: | 0.8153 g/cm3 (liquid at -20°C) | |
| Relative gas density: | 1.04 | |
| Boiling point: | -19.2°C (pure substance) | |
| Melting point: | -92.0 to -118.0°C | |
| Flash point: | 32-61°C | (aqueous solution) |
| Ignition temperature: | 300-430°C | (aqueous solution) |
| Explosion limits: | 7-73 % by vol. | |
| Solvolysis/solubility: | in water: completely soluble readily soluble in ether, alcohol and other polar solvents |
|
| Conversion factors: | 1 mg/m3 = 0.80 ppm 1 ppm = 1.25 mg/m3 |
|
ORIGIN AND USE
Usage:
The use of formaldehyde is extremely widespread and dependent on
the additives (e.g. urea, melanin, phenol, ammonia). It is thus
used in differing concentrations in adhesives (e.g. for the
production of chipboard), foams, tanning agents, explosives,
dyes, preserving agents, solvents, pharmaceuticals, resins and
fungicides.
Origin/derivation:
Formaldehyde is produced by oxidising methanol using silver or
metal oxide catalyst methods (iron and molybdenum). In addition
to the emissions resulting from the production and its usage,
formaldehyde is released into the atmosphere due to incomplete
combustion and the photochemical degradation of organic trace
substances.
Production figures:
The production figures in Germany between 1980 and 1982 were
about 500,000 tons (BMFJG, 1984). In 1978, 2.9 million tons were
produced in the USA. Japan produced 1.2 million tons of
formaldehyde in 1979 (WHO, 1982).
Toxicity
| Humans: | LDLo female 36 mg/kg, oral | acc. UBA, 1986 |
| TCLo 17 mg/m3 (30 min), inhalation | acc. UBA, 1986 | |
| TCLo 8 ppm, inhalation | acc. UBA, 1986 | |
| LDLo 477 mg/kg (unreported) | acc. UBA, 1986 | |
| Mammals: | ||
| Mouse: | LC50 300 mg/m3, subcutaneous | acc. WHO, 1982 |
| Rat: | LD50 800 mg/kg, oral | acc. WHO, 1982 |
| Rat: | LC50 590 mg/m3, inhalation | acc. WHO, 1982 |
| Rat: | LD50 87 mg/kg, intravenous | acc. WHO, 1982 |
| Rabbit: | LD50 270 mg/kg, dermal | acc. WHO, 1982 |
| Guinea pig: | LD50 260 mg/kg, oral | acc. WHO, 1982 |
| Aquatic organisms: | ||
| Small crustaceans: | LC0 27 mg/l | acc. UBA, 1986 |
| Small crustaceans: | LC50 52 mg/l | acc. UBA, 1986 |
| Small crustaceans: | LC100 77 mg/l | acc. UBA, 1986 |
| Fish: | LC100 28.4 mg/l | acc. UBA, 1986 |
| Algae: | LC50 0.3-0.5 mg/l | acc. UBA, 1986 |
| Water flea: | LC50 2 mg/l | acc. UBA, 1986 |
Characteristic effects:
Humans/mammals: Formaldehyde causes major irritation of the mucous membranes, the conjunctiva, the skin and the upper part of the respiratory tract both as a gas and as vapour or aerosol. In aqueous solutions, it is a protoplasmic poison with caustic and protein-denaturating effect. Skin contact produces surface coagulation, necroses with hardening, tanning and anaesthetisation. Swallowing or inhaling large quantities causes burning of the oesophagus or the trachea, pains in the gastro-intestinal tract, nausea, loss of consciousness and collapse. 60 ml of liquid or 650 ml of vapour per m3 are potentially lethal after a few minutes. The carcinogenic potential is a case for intense scientific discussion likely to be affirmed. Delayed and cumulative damage has not yet been established.
ENVIRONMENTAL BEHAVIOUR
Water:
Because of its good solubility, some 99% of the formaldehyde
which is released into the environment is found in water (BMFJG,
1984).
Air:
Approximately 1% of the formaldehyde emitted into the environment
reaches the atmosphere, but it is readily washed out again by
precipitation. There is no long-distance transportation due to
the relatively short half-life. Pressurised formaldehyde forms a
cold mist when depressurised. This mist is denser than air,
vaporises easily and forms aggressive and explosive mixtures with
air (including over the water surface).
Soil:
The effects of the substance in soil are unknown, however no
bioaccumulation has been established to date. Infiltration into
the groundwater is of minor concern because of the tendency of
formaldehyde to evaporate from soil.
Half-life:
The half-life in air (urban air with sun rays) is between 1 and 2
hours, or 12 hours if hydroxo radicals are present.
Degradation, decomposition products:
Degradation is performed by microorganisms in soil and water.
At temperatures above 150°C, formaldehyde decomposes to form
methanol and carbon monoxide. There is little stability under
atmospheric conditions as a result of the short half-life (BMFJG,
1984). Formaldehyde is subject to spontaneous polymerisation in
contact with acids and alkalis. It reacts with water to form
polymethylenes. When exposed to HCl, formaldehyde forms the
highly carcinogenic bis(chloromethyl)ether and catalyzes
secondary amines to form carcinogenic nitrosamines/N-nitroso
compounds.
Food chain:
There is only slight accumulation in the food chain. Formaldehyde
is rapidly oxidised in the organism to formic acid, which is
partly excreted with urine.
Combination effects:
Formaldehyde enters into vigorous condensation reactions with
ammonia or amines and is disproportionated with alkalis to form
methanol and formic acid.
ENVIRONMENTAL STANDARDS
| Medium/ acceptor | Sector | Country/ organ. | Status |
Value | Cat. | Remarks | Source |
| Air: | Emiss. | D | L | 20 mg/m3 | mass flow > 0.1 g/h | acc. TA Luft, 1986 | |
| DDR | (L) |
0.012 mg/m3 | Long-time value | acc. HORN, 1989 | |||
| DDR | (L) |
0.035 mg/m3 | Short-time value | acc. HORN, 1989 | |||
| WHO | G |
100 µg/m3 | 24 h | acc. UBA, 1988 | |||
| D | L |
0.03 mg/m3 | MIK | Long-time value | DFG, 1988 | ||
| D | L |
0.07 mg/m3 | MIK | Short-time value | DFG, 1988 | ||
| Workp | AUS | L |
3 mg/m3 | acc. WHO, 1982 | |||
| Workp | B | G |
3 mg/m3 | acc. WHO, 1982 | |||
| Workp | BG | G |
1 mg/m3 | 1) | acc. BMFJG, 1984 | ||
| Workp | CS | G |
2 mg/m3 | acc. WHO, 1982 | |||
| Workp | CS | G |
5 mg/m3 | 10 min | acc. WHO, 1982 | ||
| Workp | D | L |
0.6 mg/m3 | MAK | DFG, 1989 | ||
| Workp | D | G |
0.123 mg/m3 | 2) | acc. WHO, 1982 | ||
| Workp | DDR | (L) |
0.5 mg/m3 | Short-time value | acc. HORN, 1989 | ||
| Workp | DK | (L) |
0.148 mg/m3 | 2) | acc. WHO, 1982 | ||
| Workp | H | (L) |
1 mg/m3 | acc. WHO, 1982 | |||
| Workp | I | (L) |
1.2 mg/m3 | Long-time value | acc. WHO, 1982 | ||
| Workp | I | (L) |
0.12 mg/m3 | acc. BMFJG, 1984 | |||
| Workp | J | (L) |
2.5 mg/m3 | acc. WHO, 1982 | |||
| Workp | NL | L |
1.2 mg/m3 | acc. BMFJG, 1984 | |||
| Workp | NL | G |
0.12 mg/m3 | 2) | acc. BMFJG, 1984 | ||
| Workp | PL | G |
2 mg/m3 | acc. WHO, 1982 | |||
| Workp | RO | G |
4 mg/m3 | 3) | acc. WHO, 1982 | ||
| Workp | S | (L) |
3 mg/m3 | 10 min3) | acc. WHO, 1982 | ||
| Workp | S | (L) |
0.6 mg/m3 | 4) | acc. BMFJG, 1984 | ||
| Workp | S | (L) |
0.12 - 0.5 mg/m3 | acc. BMFJG, 1984 | |||
| Workp | S | G |
0.123 mg/m3 | 2) | acc. WHO, 1982 | ||
| Workp | SF | (L) |
1.2 mg/m3 | acc. BMFJG, 1984 | |||
| Workp | SF | G |
3 mg/m3 | acc. WHO, 1982 | |||
| Workp | SU | (L) |
0.5 mg/m3 | PDK | 3) | acc. SORBE, 1988 | |
| Workp | USA | (L) |
1.5 mg/m3 | TWA | acc. SORBE, 1988 | ||
| Workp | USA | (L) |
3 mg/m3 | STEL | 30 min | acc. WHO, 1982 | |
| Workp | USA | (L) |
0.13 mg/m3 | acc. BMFJG, 1984 | |||
| Workp | USA | (L) |
0.6 mg/m3 | 5) | acc. BMFJG, 1984 | ||
| Workp | YU | (L) |
1 mg/m3 | acc. WHO, 1982 |
Further legislation:
- The concentration levels in chipboard in the Federal Republic of Germany must not exceed the following (ETB, 1980): Emission class 1 (E1) max. 0.1 ppm; emission class 2 (E2) max. 1 ppm; emission class 3 (E3) max. 2.3 ppm. There are no regulations to date regarding the use of chipboard in furniture and in the Do-it-yourself sector.
- There are similar regulations in Belgium and Japan (chipboard classification).
- The maximum concentration levels in the Federal Republic of Germany for finished products are as follows for cosmetics (Order Governing Cosmetics, 1977): nail hardeners: 5%; preservative agent: 0.2%; mouthwash 0.1%
- The quality requirements imposed on urea-resin in-situ foams used for insulation are regulated in the Federal Republic of Germany by DIN Standard 18159.
- There is a total ban on UF foam insulation in Canada.
- The Japanese likewise control the concentration in wallpapers and adhesives and there is a ban on formaldehyde as an additive in the treatment and packaging of foodstuffs as well as in paints. The substance is limited to 75 ppm in textiles (BMJFG, 1984).
Notes:
1) For stationary systems
2) Indoor air
3) Maximum value
4) For new systems
5) Minnesota
Comparison/reference values
| Medium/origin | Country | Value | Source |
| Air: | |||
| Los Angeles, California (1961-66): | USA | 0.005-0.16 mg/m3 | acc. BMJFG, 1984 |
| Road air (1977) | CH | 0.0011-0.0012 mg/m3 | acc. BMJFG, 1984 |
| Sea air (1979) | D | 0.00012-0.008 mg/m3 | acc. BMJFG, 1984 |
| Automobile emissions | 35.7-52.9 mg/m3 | acc. BMJFG, 1984 | |
| Interior of house (1975): | DK | 0.08-2.24 mg/m3 | acc. BMJFG, 1984 |
| Indoor air (BMJFG, 1984; Tests between 1975 and 1984): | |||
| Chipboard: | |||
| New schools | 0.36-1.08 mg/m3 (little exchange of air) | ||
| Classrooms and homes | 0.6-0.72 mg/m3 (furniture) | ||
| Prefabricated house | 0.18-1.08 mg/m3 | ||
| Houses in USA | 0.012-3.84 mg/m3 (636 houses) | ||
| Thermal insulation | 0.24-3.48 mg/m3 (43 properties) | ||
| Disinfection: | |||
| Pathology | < 13.56 mg/m3 (following removal) | ||
| Bed disinfection | < 6 mg/m3 | ||
| Disinfection by scrubbing | < 13.2 mg/m3 | ||
| Spray disinfection | < 12 mg/m3 | ||
| Incubator air | 18-30 mg/m3 | ||
| Rainwater: | |||
| Mainz (1974-1977) | D | 0.174 ± 0.085 µg/l | acc. BMJFG, 1984 |
| Deuselbach (1974-1976) | D | 0.141 ± 0.048 µg/l | acc. BMJFG, 1984 |
| Clean-air zone (1977) | IRL | 0.111 ± 0.059 µg/l | acc. BMJFG, 1984 |
| Foodstuffs and semi-luxury goods: | |||
| Tomatoes | 5.7-7.3 µg/kg | acc. WHO, 1982 | |
| Apples | 17.3-22.3 µg/kg | acc. WHO, 1982 | |
| Spinach | 3.3-7.3 µg/kg | acc. WHO, 1982 | |
| Carrots | 6.7-10 µg/kg | acc. WHO, 1982 | |
| Radish | 3.7-4.4 µg/kg | acc. WHO, 1982 | |
| Cigarette smoke | 37.5-44.5 µg/cigarette | acc. WHO, 1982 | |
Assessment/comments
Workplace exposure is not the only way by which formaldehyde enters the human body. Its use as an adhesive in the manufacture of chipboard and its mixing with urea for in-situ foams is controlled both in Germany and in several other countries. When the above building materials are used, formaldehyde degases into the air inside residential buildings. The carcinogenic potential of formaldehyde has yet to be reliably established. Isolated animal experiments point to the possibility of a carcinogenic and teratogenic effect.
Special sources: BMFJG (1984)