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EC number: 949-694-5
CAS number: -
There is no requirement to generate experimental toxicokinetic data
under REACH. No toxicokinetic data are identified;
however a theoretical assessment of the toxicokinetic properties of the
substance is made, based on existing toxicity data, and taking into
account the physico-chemical properties of the substance.
The following information is taken into
account for any hazard / risk assessment:
Micromica is a synthetic mica, a
silicate mineral. Compositional analysis shows that Micromica is
predominantly silicon dioxide (SiO2) and magnesium oxide (MgO), with
smaller proportions of potassium oxide (K2O) and fluoride (F).
Under standard conditions, Micromica is
a white crystalline powder, essentially insoluble in water. On this
basis, it would be expected that Micromica would be poorly absorbed
after oral administration. This prediction is supported by acute oral
toxicity data on micromica, which reported an oral LD50 >5000 mg/kg bw,
and on synthetic mica, in which “no adverse clinical signs or physical
findings” were reported, with a reported oral LD50 >9000 mg/kg bw.
Repeated-dose oral toxicity studies on the chemically and structurally
similar material (synthetic mica) also found a lack of effects, even at
doses as high as 5000 mg/kg bw/day (for 90 days), indicating a lack of
absorption. A health-precautionary value of 5% has been taken forward
for chemical safety assessment.
structure, composition and very low aqueous solubility, dermal
absorption is not expected. No systemic toxicity data using dermal
administration are available, but there is no indication from local
irritation studies that Micromica can penetrate the skin. A
health-precautionary value of 5% has been taken forward for chemical
The mean particle size (D50) of
Micromica is 8.376 μm, with a D10 of 3.65 μm and a D90 of 16.49 μm.
Particle sizes below 10 μm are generally considered inhalable (i.e. able
to reach the thoracic and alveolar regions of the lungs), and thus have
the potential to cause adverse health effects after inhalation exposure.
An acute inhalation toxicity study on a related substance did not find
any effects even at the limit concentration (LC50 > 5.1 mg/L),
indicating that even if Micromica were to reach the thoracic and
alveolar regions of the lungs, it would not be absorbed. Nevertheless, a
highly health-precautionary value of 100% has been taken forward for
chemical safety assessment.
Distribution, Metabolism and Excretion
it is essentially insoluble, if a small portion of Micromica was
systemically absorbed, it would not be expected to be widely distributed
to the tissues. As a crystalline, inorganic material, normal enzymatic
metabolism would not be expected to effect any biotransformation on
Micromica. The most likely outcome is excretion through the bile and
faeces, with the substance essentially unchanged.
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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