Talc (Mg3H2(SiO3)4)

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Data waiving:

other justification

Justification for data waiving:

other:

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

QSAR prediction: US EPA accepted QSAR method for chemicals properties assessment.

Qualifier:

according to guideline

Guideline:

other: QSAR model

Principles of method if other than guideline:

ECOSAR Program(v1.00)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

other: Green Algae

Details on test organisms:

QSAR model-Green Algae

Test type:

other: QSAR model

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

not applicable. QSAR model

pH:

not applicable. QSAR model

Dissolved oxygen:

not applicable. QSAR model

Salinity:

not applicable. QSAR model

Nominal and measured concentrations:

not applicable. QSAR model

Details on test conditions:

Chem Name : Talc (Mg3H2(SiO3)4)
Molecular Wt: 379.27
Henry's LC : 5.54e-029 atm-m3/mole (calc VP/Wsol)
Vapor Press : 1.11e-022 mm Hg (Mpbpwin program)
Liquid VP : 1.15e-019 mm Hg (super-cooled)
Melting Pt : 330 deg C (Mpbpwin program)
Log Kow : -9.4 (Kowwin program)
Soil Koc : 31.82 (KOCWIN MCI method)

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

7 202.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: (Q)SAR prediction

Duration:

30 d

Dose descriptor:

NOEC

Effect conc.:

918.089 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: (Q)SAR prediction

Details on results:

A 96 h LC50 value of 7202.700 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group..This result signifies that the test substance is not expected to be toxic. A NOEC value of 918.089 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group. This result signifies that the test substance is not expected to be toxic.

Reported statistics and error estimates:

Green Algae, 96-hr EC50 =  7202.700 mg/L (ppm)

Overview of QSARs estimations onaquatic toxicity of  Talc (Mg3H2(SiO3)4) to Green algae

 

Method	Results	Remarks	Reference
QSAR estimate	Green Algae, 96-hr EC50 =7202.700 mg/L (ppm) Green Algae, 30-day, NOEC cited as a ChV value = 918.089 mg/L (ppm)	Reliable with restrictions, QSAR estimated data	ECOSAR Program (v1.00)

 

 

Green Algae, 96-hr EC50 =7202.700 mg/L (ppm)

Green Algae, 30-day, NOEC cited as a ChV value = 918.089 mg/L (ppm)

Validity criteria fulfilled:

yes

Remarks:

method for chemicals properties assessment.

Conclusions:

A 96 h LC50 value of 7202.700 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group..This result signifies that the test substance is not expected to be toxic. A NOEC value of 918.089 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group. This result signifies that the test substance is not expected to be toxic.

Executive summary:

A 96 h LC50 value of 7202.700 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group..This result signifies that the test substance is not expected to be toxic.

A NOEC value of 918.089 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group. This result signifies that the test substance is not expected to be toxic.

Description of key information

The substance is almost insoluble in aqueous solution and Talc (Mg3H2(SiO3)4) is not expected to be harmful to aquatic life. Talc represents of hydrated magnesium silicate and Silicates are necessary for healthy algal growth. On the basis that there is no evidence that Talc is toxic to algae in naturally occurring Silicate species in the aquatic environment, it is highly unlikely that the Silicate species would cause any different effect so testing for this end point has been waived as being scientifically unjustified. Therefore testing for Toxicity to aquatic algae and cyanobacteria does not need to be performed.

A 96 h LC50 value of 7202.700 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group..This result signifies that the test substance is not expected to be toxic.

A NOEC value of 918.089 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group. This result signifies that the test substance is not expected to be toxic.

Key value for chemical safety assessment

EC50 for freshwater algae:

7 202.7 mg/L

EC50 for marine water algae:

720.27 mg/L

EC10 or NOEC for freshwater algae:

918.089 mg/L

EC10 or NOEC for marine water algae:

91.81 mg/L

Additional information

The available data for marine water algae and cyanobacteria are limited and to obtaine the value for PNECs for saltwaters is taken account a assesment factor 10 to extrapolate to LC50 following the “Guidance on Information Requirement and Chemical Safety Assessment R.10: Characterisation of dose [concentration]- response for environment”and “Table R.10-5 Assessment factors proposed for deriving PNEC water for saltwater for different data sets”, to account for the possibility that greater taxonomic diversity in the marine environment makes it likely that some marine taxa may be more sensitive than the most sensitive freshwater taxa.