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EC number: 222-720-6
CAS number: 3586-55-8
Phototransformation of the test substance
was calculated using generally accepted method EPI suite AOPWIN. The
following results were obtained: PHOTOCHEMICAL REACTION WITH OH RADICALS
Concentration of OH radicals: 500000 Degradation rate constant:
0.0000000000083217 cm³/molecule-sec Temperature for which rate constant
was calculated: 25 °C Calculated t 1/2 is based on a 24 h day. The
halflife of ethylene glycol in air is estimated to DT50 = 46.3 h. Hydrolysis
of the test substance was studied using 13C-NMR techniques andspectrophotometric
analysis. The degree of hydrolysis was measured by detection of
formaldehyde. During the reaction time, increasing amounts of
formaldehyde were observed. At all pH values, the content of
formaldehyde reached a plateau, an equilibrium between the reactants was
observed. The studies demonstrate the rapid hydrolysis. At
large dilutions which are expected under environmental conditions (in
wastewaters or surface waters) as well as in human body fluids, the test
substance is expected to hydrolyse completely to formaldehyde and
Information on formaldehyde
Hydrolysis and phototransformation in
Hydrolysis of formaldehyde can be
excluded because of the absence of a hydrolysable group in the molecule.
Therefore, a test on hydrolysis in water is scientifically unjustified.
There are no tests on photolysis of formaldehyde in aqueous solutions
available which would allow deriving a reaction rate for surface waters.
In aqueous solutions formaldehyde hydrate is formed which has no
chromophore that is capable of absorbing sunlight and thus should not
decompose by direct photolysis. The reaction of formaldehyde with
OH-radicals (indirect photolysis) was studied in cloud water. However,
because of the different composition of aerosols compared to surface
waters the reaction rate obtained for aerosol cannot be adopted for the
oxidation in surface waters. Because of the ready biodegradability,
photolysis in surface waters is expected to be of minor importance. In
conclusion, a test on phototransformation in water would not improve the
database for the hazard assessment and is therefore scientifically
aqueous solutions, formaldehyde forms the hydrate CH2(OH)2.
Monomeric, physically dissolved formaldehyde is only present in low
concentrations of up to 0.1 wt %. The polymerization equilibrium HOCH2OH
+ n CH2ODHO(CH2O)n+1−H
is catalyzed by
acids and is shifted toward the right at lower temperature and/or higher
formaldehyde concentrations, and toward the left if the system is heated
and/or diluted. At environmental relevant concentrations, formaldehyde
is expected to exist predominantly as hydrate. Paraformaldehyde
dissolves slowly in cold water, but readily in warm water where it
undergoes hydrolysis and depolymerization to give a formaldehyde
solution (Ullmann 2005).
Phototransformation in air
In the gas phase, formaldehyde is
rapidly degraded in air via reaction with OH radicals; degradation by
nitrate and ozone is negligible. The decomposition by direct photolysis
is 1.5 times higher than by OH radicals. The main transformation
products are hydrogen and carbon monoxide. In cloud water, formaldehyde
hydrate reacts with OH-radicals (indirect photolysis) to form formic
acid (Chameides and Davies 1983). Based on the half-life constants of
formaldehyde, accumulation in the atmosphere is not to be expected.
Furthermore, the Henry's law constant is relatively low. Therefore,
formaldehyde is not expected to volatilise to air from water surfaces in
significant quantities and the amount which reaches the air compartment
will be washed out by rain.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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