Registration Dossier

Ecotoxicological information

Toxicity to aquatic plants other than algae

Currently viewing:

Administrative data

Endpoint:
toxicity to aquatic plants other than algae
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
1983 to 1985
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The EU RAR summarises the results of two studies which have limitations regarding study design and reliability. However, the results of these studies, on four species, combined with data on algae, provide an adequate assessment of toxicity to primary producers in the aquatic compartment.

Data source

Reference
Reference Type:
review article or handbook
Title:
European Union Risk Assessment Report: chromium trioxide, sodium chromate, sodium dichromate, ammonium dichromate and potassium dichromate
Author:
European Chemicals Bureau
Year:
2005
Bibliographic source:
3rd. Priority List; Volume 53

Materials and methods

Test guideline
Qualifier:
no guideline followed
Guideline:
other: different studies included
Deviations:
not applicable
Principles of method if other than guideline:
Two studies on four species, collectively, provide an adequate assessment of toxicity to aquatic plants.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
No further details provided

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Range of methods used

Test solutions

Vehicle:
no
Details on test solutions:
Range of media used

Test organisms

Test organisms (species):
other: Lemna gibba, Lemna minor, Spirodela polyrhiza and Spirodela punctata

Study design

Test type:
other: Different test designs
Water media type:
freshwater
Limit test:
no
Remarks on exposure duration:
Range used
Post exposure observation period:
Not indicated

Test conditions

Hardness:
Range from different tests
Test temperature:
Range from different tests
pH:
Range from different tests
Dissolved oxygen:
Range from different tests
Salinity:
Range from different tests
Nominal and measured concentrations:
Range from different tests
Details on test conditions:
Range from different tests
Reference substance (positive control):
no

Results and discussion

Any other information on results incl. tables

The results of the studies evaluated in the EU RAR are summarised below:

Species

Endpoint:
growth (g)
biomass (b)

Value (mg/L)

Reference

Lemna gibba

8 d NOEC (g)

0.1b,d

Staves and Knaus (1985)

Lemna minor

7 d NOEC (g)

0.11

Sloof and Canton (1983)

Spirodela polyrhiza

8 d NOEC (g)

0.1b,d

Staves and Knaus (1985)

Spirodela punctata

8 d NOEC (g)

0.5a,b,d

Staves and Knaus (1985)

a NOEC calculated as LOEC/2 from paper, effect of 14%; (b) - biomass; (g) ¿ growth

b sodium chromate tested; all others used potassium dichromate. All concentrations as Cr.

d study rated as IIIb

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Based on a review of data on algae and aquatic plants, the data from the EU RAR provides an acceptable assessment of toxicity to aquatic primary producers.
Executive summary:

From two studies with four species, the 7 to 8 day NOEC values (growth) to aquatic plants range from 0.1 to 0.5 mg/L, based on tests with potassium dichromate and sodium chromate.

Where comparison is possible, the toxicity of sodium chromate or sodium dichromate, when expressed on a total chromium basis, does not appear to be significantly different from that of potassium dichromate. This is as would be expected if the equilibria between the chromate and dichromate anions are established in the test medium. Little information is available for ammonium dichromate and chromic acid, but it would be expected that their toxicity would be similar to that of the other chromates/dichromates, when expressed on a total chromium concentration basis.