Fumes, silica

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12.07.2011-03.08.2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

yes

Remarks:

Elendt's M4 or M7 medium are according to OECD 211 not suitable for testing with chemicals containing metals. Therefore, the US EPA hardwater medium was used. Only one concentration (100 mg/L was used).

Principles of method if other than guideline:

Existing information indicate that acute lethal effects are not very likely at the level of solubility e.g. at 100 mg/l nominal load or even at remarkably higher loads. Therefore long term test could be carried out without a prerequisite (range finding) short term test.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Fumes, silica

EC Number:

273-761-1

EC Name:

Fumes, silica

Cas Number:

69012-64-2

Molecular formula:

SiO2

IUPAC Name:

silanedione

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Purity 83.8% amorphous SiO2

Sampling and analysis

Analytical monitoring:

not specified

Test solutions

Vehicle:

yes

Details on test solutions:

100 mg of silica fume was loaded into 1 L of US EPA hardwater media.
Composition of the test solution:
CaSO4*2H2O 120 mg/L
MgSO4*7H2O 246.4 mg/L
KCl 8 mg/L
NaHCO3 192 mg/L

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Strain: Starus (Clone A)
Source: continuous culture at NIVA

Study design

Test type:

semi-static

Total exposure duration:

21 d

Test conditions

Test temperature:

20 ± 2°C

Nominal and measured concentrations:

The daphnids were fed a mixed algal diet consisting of Pseudokirchneriella subcapitata and Chladymonas reinhardtii at a rate sufficient to provide 0.1-0.2 mg carbon/daphnid/day.

Results and discussion

Effect concentrations

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: mortality, reproduction, growth

Details on results:

.

Applicant's summary and conclusion

Conclusions:

The data generated during the study indicated that there were no effects on survival, growth (length) and reproduction of Daphnia magna exposed to an initial nominal loading concentration of 100 mg/L Silica fume (low grade) after 21 days exposure. Therefore the NOEC for Daphnia magna reproduction and growth (length) for Silica fume (low grade) is at an initial loading concentration of 100 mg/L.

Executive summary:

The effects of Silica fume (low grade) on Daphnia magna were studied in a 21 -day study performed according to OECD test guideline 211. The data showed that Silica fume (low grade) did not cause a reduction in the number off offspring produced, the length of the organisms at the end of the study or the survival when comapred to control organisms. The NOEC was at an initial loading concentration of 100 mg/L.