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EC number: 908-343-6
CAS number: -
REACH registration dossier of the ‘reaction mass of calcium carbonate,
calcium hydroxide and calcium peroxide’, several ecotoxicity endpoints
were assessed based on test data that are available for hydrogen
peroxide and calcium hydroxide, the two primary degradation products
resulting from the hydrolysis of calcium peroxide.
described in the section on environmental fate and pathways, hydrogen
peroxide is a degradation product that is formed upon hydrolysis of
calcium peroxide. In ECHA’s Guidance document on information
requirements and chemical safety assessment it is mentioned that testing
on the hydrolysis product can be justified if the DT50 (50%
disappearance time) is very short, i.e. less than 3 days.
+ 2 H2O --> Ca2
++ 2 (OH)- + H2O2
+ H2O --> 2
H2O + O2
Ca(OH)2 --> Ca2++
CaCO3 --> Ca2++
of calcium peroxide can be estimated from the water solubility study:
As 100 mg
of the ‘reaction mass of calcium carbonate, calcium hydroxide and
calcium peroxide’ contains 77.5 mg of calcium peroxide, the test
show that the hydrolysis of 77.5 mg/L calcium peroxide in
water occurs within 24 hours under the conditions of the test (double
distilled water, 20°C). As a consequence, the DT50 for
the disappearance of calcium peroxide in an aqueous
environment will be well below 24 hours.
the use of test results obtained for its hydrolysis product hydrogen
peroxide for the assessment of ecotoxicological endpoints of
the REACH registration dossier is considered acceptable and justified.
It is to be noted that the hydrogen peroxide that is formed
upon hydrolysis of calcium peroxide itself undergoes further
According to the applicable chemical
reaction (see above), the amount of hydrogen peroxide formed
is equimolar to the amount of calcium peroxide present in the
reaction mass. As the concentration of calcium peroxide in
the reaction mass is ca. 75%, 100 mg of the reaction mass contains 75 mg
of calcium peroxide, which corresponds to 1.04 mmol of calcium peroxide.
Therefore, 1.04 mmol (= 35.36 mg) of hydrogen peroxide is
formed upon dissolution of 100 mg of the reaction mass.
For example, a 96h-LC50 of
16.4 mg/L for hydrogen peroxide can be extrapolated to result in the
following 96h-LC50 for the reaction mass of calcium carbonate
and calcium dihydroxide and calcium peroxide:
100 mg/L reaction
mass yields 35.36
mg/L hydrogen peroxide
mg/L reaction mass yields 16.4
mg hydrogen peroxide
The extrapolated 96h-LC50 for
the multi-constituent substance is: 46.4 mg/L.
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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