Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 908-343-6
CAS number: -
No experimental data are available that assess the short-term toxicity
of the reaction mass of calcium carbonate and calcium dihydroxide and
calcium peroxide to fish. Nevertheless, a 96h-LC50 value can be derived
from reliable information that is available for hydrogen peroxide.
The 96h-NOEC for the reaction mass is 14,14 mg/L.
The 96h-LC50 for the reaction mass is 46.38 mg/L
No experimental data are available that
assess the short-term toxicity of the reaction mass of calcium
carbonate and calcium dihydroxide and calcium peroxide to fish.
Nevertheless, for this endpoint reliable information is available
for hydrogen peroxide (H2O2) and calcium hydroxide
(Ca(OH)2), the primary hydrolytic degradation products of the reaction
mass of calcium carbonate and calcium dihydroxide and calcium peroxide.
For calcium dihydroxide, the
short-term toxicity test with Oncorhynchus mykiss (rainbow trout)
(Egeler et al., 2007) was carried out according to the OECD 203 guidance
taking into account GLP and thus resulting in a Klimish 1 score. The
biological findings for Oncorhynchus mykiss were closely related to the
initial pH of the test solutions, which ranged from 7.8 in the controls
to 9.6, 9.9, 10.4, 10.8 and 11.1 at nominal concentrations of 14.8,
22.2, 33.3, 50 and 75 mg Ca(OH)2/L, respectively. Therefore
the initial pH is considered to be the main reason for the effects of
calcium dihydroxide on the fish. The 96h-LC50 was found to be
50.6 mg/L under the conditions of this test.
The key study assessing the acute
toxicity of hydrogen peroxide to fish as identified in the REACH
registration dossier for hydrogen peroxide dates from 1989
and is performed according to US EPA guidelines (Shurtleff, 1989). In
this semi-static experiment, Pimephales promelas (fathead minnow) were
exposed for 96 hours to nominal hydrogen peroxide concentrations
of 0.5, 5, 25, 50 and 250 ppm. The test solutions were replaced every
day. The 96h-LC50 was found to be 16.4 mg/L (95% confidence interval:
13.1 -20.5 mg/L), and the 96h-NOEC value was 5 mg/L. As the 96h-LC50
value for hydrogen peroxide is lower than the value found for calcium
dihydroxide, the former was selected for the assessment of the reaction
From this 96h-LC50 value a
corresponding 96h-LC50 value can be calculated for the reaction mass, by
taking into account the applicable chemical reaction (i.e. the amount of
hydrogen peroxide formed is equimolar to the amount of
calcium peroxide present in the reaction mass) and the
composition of the reaction mass (i.e. the reaction mass contains ca.
75% calcium peroxide).
Thus: 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 calcium peroxide.
As a consequence, the 96h-LC50 for
the reaction mass can be calculated from the 96h-LC50 for
hydrogen peroxide (16.4 mg/L):
100 mg reaction
mass yields 35.36 mg hydrogen peroxide
mg reaction mass yields 16.4
mg hydrogen peroxide
96h-LC50 (reaction mass)
= 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.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again