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Ecotoxicological information

Toxicity to aquatic plants other than algae

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Administrative data

Endpoint:
toxicity to aquatic plants other than algae
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: Test method was similar to OECD guideline 221. However, no data on analytical monitoring. No data on GLP.

Data source

Reference
Reference Type:
publication
Title:
Haloacetic acids in the aquatic environment. Part I: macrophyte toxicity.
Author:
Hanson ML, Solomon KR
Year:
2004
Bibliographic source:
Environmental Pollution 130 (2004) 371-383
Report Date:
2003

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 221 (Lemna sp. Growth Inhibition Test)
Deviations:
not specified
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): TCA
- Analytical purity: 99.7 %

Sampling and analysis

Analytical monitoring:
not specified

Test solutions

Vehicle:
yes
Details on test solutions:
The acid solutions were titrated to the required growth media pH with sodium hydroxide.

Test organisms

Test organisms (species):
Lemna gibba
Details on test organisms:
L. gibba was cultured axenically according to the methods outlined in Greenberg et al. (1992) with Hunter’s media containing 10 g/L sucrose. Culturing was conducted in a laminar flowhood.

Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
7 d

Test conditions

Test temperature:
25 ± 2 ºC
Nominal and measured concentrations:
Nominal concentrations: 3, 10, 30, 100, 200, 400, and 800 mg/L.
Details on test conditions:
Approximately 10 days prior to a L. gibba toxicity test, plants were transferred from growth media containing sucrose to media without sucrose. This
was done so that the plants would switch from heterotrophic to autotrophic energy production.
L. gibba testing was conducted according to the methods outlined in Greenberg et al. (1992) with growth chamber conditions maintained under standard conditions for this test.
The growth chamber was a model E7H Controlled Environments chamber.
Light was maintained for 24 h at approximately 6200 lux.
Each test solution was transferred to a 10-mL plastic Petri dish (Fisher Scientific) and two plants, each with four fronds, for a total of eight fronds, were introduced and monitored.
Test solutions were changed on day 3 and 5 to maintain consistent levels of the compound under study.

- Control: n=6
- Exposed plants: n=3

The endpoints monitored were frond number, colony number, wet mass, frond mass, frond growth rate and chlorophyll a, chlorophyll b, and total chlorophyll concentrations. Pigment concentrations were determined simultaneously by extraction in ACS grade N,N'- dimethyl formamide (Fisher Scientific, Fair Lawn, NJ, USA) using the method and calculations outlined by Porra et al. (1989) and measured with a PU8620 Series UV/visible Spectrophotometer (Philips Analytical, Natick, MA, USA) on a fresh-weight basis.
Reference substance (positive control):
not specified

Results and discussion

Effect concentrationsopen allclose all
Duration:
7 d
Dose descriptor:
EC50
Effect conc.:
864.3 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: (95% CL = 575.2-1153.3)
Duration:
7 d
Dose descriptor:
other: EC25
Effect conc.:
215.8 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: (95% CL = 129.6-302.0)
Duration:
7 d
Dose descriptor:
EC10
Effect conc.:
53.9 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: (95% CL = 10.8-96.9)
Details on results:
The most sensitive endpoint was the Frond number and pigments was the least sensitive endpoint.

Any other information on results incl. tables

The EC50 was 864.3 (575.2 -1153.3) mg/L (basis for effect: growth rate).

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Remarks:
(No data on control results)
Conclusions:
The EC50 was 864.3 (575.2 -1153.3) mg/L (basis for effect: growth rate).
Executive summary:

Laboratory tests were conducted with the macrophyte Lemna gibba to assess the toxicity of Trichloroacetic acid.

The EC50 was 864.3 (575.2 -1153.3) mg/L (basis for effect: growth rate).

The most sensitive endpoint was the Frond number and pigments was the least sensitive endpoint.