Refractories, fibers, aluminosilicate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19th March 2010 to 29th March 2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The method is not strictly adapted to the study of glasses, which are only loosely speaking polymers being 3 dimensional polymeric silicates, which fail in aqueous environments and do not dissolve nor release extractable materials.

Qualifier:

according to guideline

Guideline:

other: OECD 120

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Water solubility:

ca. 0.02 mg/L

Temp.:

20 °C

pH:

ca. 7

Details on results:

Refer to table 1 and 2 in the results sections

Table 1

Nominal loading rate	sample	Mass of test item (g)	Volume of test medium
1g/l	A	0.5055	500ml
	B	0.5017	500ml
	C	0.5035	500ml
10g/l	A	5.0284	500ml
	B	5.0713	500ml
	C	5.0972	500ml

Table 2 Overall results

Nominal loading rate	measurement	Equivalent mean (SiO2)n concentration
1.0g/l	Solution concentration	0.0216 mg/l
	Per unit mass of test item	0.0215 mg/l
10g/l	Solution concentration	0.0996mg/l
	Per unit mass of test item	0.0984mg/l

Conclusions:

There was significant (99.5%) recovery of undissolved test item indicating in this method that the substance is essentially insoluble with regards to 1mg/l. criteria. Actual solubility as one of these deficiencies of this method is that the test article is a solid and a fibre, which sticks to the glass ware and is retained in the meniscus of any suspension these loses are not accounted for in any calculated results. The OECD method does not lend itself to fibrous inorganic materials.

Executive summary:

The material is insoluble in water

Description of key information

Solubility indeterminate but SiO2 and Al2O3 can be measured in the water in which fibres have been soaked. Loss of mass in the method used is due to fibres being trapped due to their large surface area/mass ratio on the surface of the apparatus used and at the meniscus at the water/air interface.

Key value for chemical safety assessment

Water solubility:

1 mg/L

at the temperature of:

20 °C

Additional information

This material is not truly soluble but a can release silica and some species of aluminium hydroxide or its degradation products. In general the aluminosilicate glasses are less "soluble" than other types of glass such as those used in making laboratory glassware.