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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Toxicity to aquatic plants other than algae

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Administrative data

Link to relevant study record(s)

Reference
Endpoint:
toxicity to aquatic plants other than algae
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Peer-reviewed technical publication that meets basic scientific principles.
Qualifier:
equivalent or similar to guideline
Guideline:
EPA OPPTS 850.4400 (Aquatic Plant Toxicity Test using Lemna spp. Tiers I & II))
Deviations:
yes
Remarks:
no further details available
GLP compliance:
not specified
Analytical monitoring:
yes
Details on sampling:
On day 1, 4, 7 and 10, three 24h samples for each concentration were collected.
All samples were stored at 4°C until analysis.
Vehicle:
no
Test organisms (species):
other: Spirodella polyrrhiza
Details on test organisms:
TEST ORGANISM
- Common name: Duckweed
- Source : existing laboratory culture
Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
10 d
Test temperature:
25 +- 1 °C
Nominal and measured concentrations:
Nominal concentrations : 0.5, 3, 6, 17, 25 and 37 mg B/L
To verify B exposure, water samples were analyzed using the colorimetric curcumin method as described by Allen (1974). Mean concentrations of time 0 and 24 hr samples were: 0.9 (control), 3.6, 6.5, 19.2, 24.0, and 40.0 mg B/L. B concentrations for days 4, 6 and 10 were not reported. Authors expressed endpoints based on time 0 concentrations, but mean values are used below.
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 50 ml plastic cups filled with 45 ml of boron-containing nutrient media
- Renewal rate of test solution (frequency/flow rate): daily
- No. of fronds per colony: 14-16
- No. of vessels per concentration (replicates): 6


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: pH stabilized nutrient media (Clatworthy and Harper, 1962)


OTHER TEST CONDITIONS
- Photoperiod, light intensity and quality: 24h light from normal chamber illumination + two 24-in. Lampi Flora Plant lights each fitted with 20 W wide-spectrum fluorescent lights were placed +- 12 in. above the test chambers.


EFFECT PARAMETERS MEASURED :
- Determination of frond number: On day 0 and 10,frond number was determined, and observations of fronds were made. Chlorosis, necrosis and death were observed and classified as abnormal fronds.

Duration:
10 d
Dose descriptor:
LOEC
Effect conc.:
3.6 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Basis for effect:
frond number
Duration:
10 d
Dose descriptor:
NOEC
Effect conc.:
6.5 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Basis for effect:
growth rate
Duration:
10 d
Dose descriptor:
LOEC
Effect conc.:
19.5 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Basis for effect:
growth rate
Details on results:
Total frond production reduced at next higher exposure (3.6 mg B/L) so no NOEC for total frond number can be derived. EC10 values could not be calculated
Reported statistics and error estimates:
Statistical analysis was performed using TOXSTAT 3.5 and ANOVA. The ANOVA and Tukey's HSD were performed to measure statistical differences between boron concentrations on days 0 and 10. These statistical tests were also used to analyze differences in initial concentrations and 24-h sample boron concentrations. Significance was determined using p =< 0.05 for all statistical tests.
Duration Endpoint Effect conc. Nominal/Measured Conc. based on Basis for effect Remarks (e.g. 95% CL)
10 d LOEC 3.6 mg/L meas. (not specified) element frond number unbounded LOEC
10 d EC50 14.3 mg/L meas. (not specified) element frond number
10 d NOEC 6.5 mg/L meas. (not specified) element growth rate
10 d LOEC 19.2 mg/L meas. (not specified) element growth rate
10 d EC50 11.7 mg/L meas. (not specified) element growth rate

Description of key information

The test item boric acid has been evaluated for its toxicity towards the aquatic plant Spirodella polyrrhiza in a study according to EPA OPPTS 850.4400 (Aquatic Plant Toxicity Test using Lemna spp. Tiers I & II). The fresh water plant has been exposed to nominal concentrations of 0.5, 3, 6, 17, 25 and 37 mg B/L for a total of 10 days under semi-static conditions. The EC50 growth rate and NOEC growth rate have been determined to be 11.7 mg B/L and 6.5 mg B/L, respectively.

Key value for chemical safety assessment

EC50 for freshwater plants:
11.7 mg/L
EC10 or NOEC for freshwater plants:
6.5 mg/L

Additional information