Benzyltriethylammonium chloride

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04.11.2016 – 07.11.2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard test guidelines

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

no

Analytical monitoring:

yes

Details on sampling:

No data

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION The solution 100 mg/L was prepared by dissolving white powder in OECD growth medium and it was inoculated by culture. The substance was declared as light sensitive.- Controls: OECD medium as specified in OECD 201, used as a control and for dilution of the stock solution.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM - Strain: 86.81 SAG - Source (laboratory, culture collection): Institute of botany of the ASCR - Age of inoculum (at test initiation): 5x103 cells/ml - Method of cultivation: No data ACCLIMATION - Acclimation period: No data - Culturing media and conditions (same as test or not): No data - Any deformed or abnormal cells observed: No data

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Remarks on exposure duration:

±1 hour

Post exposure observation period:

No data

Hardness:

No data

Test temperature:

23°C ± 2°C

pH:

The sample at concentration 100 mg/L : pH = 7.9 did not change during the test, Control : pH = 8.2 changed to pH = 7.8 during the test

Dissolved oxygen:

No data

Salinity:

No data

Conductivity:

No data

Nominal and measured concentrations:

No data

Details on test conditions:

TEST SYSTEM - Test vessel: 50ml glass vessel - Type : closed (with air-permeable stopper) - Material, size, headspace, fill volume: 15 ml - Aeration: No data - Type of flow-through (e.g. peristaltic or proportional diluter): No data - Renewal rate of test solution (frequency/flow rate): No data - Initial cells density: 5x103 cells/mL - Control end cells density: No data - No. of organisms per vessel: No data - No. of vessels per concentration (replicates): 6 - No. of vessels per control (replicates): No data - No. of vessels per vehicle control (replicates): No data GROWTH MEDIUM - Standard medium used: Yes OTHER TEST CONDITIONS - Adjustment of pH: Without adjustment - Photoperiod: Continuous - Light intensity and quality: 6000 lx - 8000 lx EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : - Determination of cell counting: Electronic particle counter. - Chlorophyll measurement: No - Other: EC50 was calculated

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: No significant difference p = 0.704

Details on results:

No data

Results with reference substance (positive control):

- Results with reference substance valid- ErC50: 0.69 mg/L K2Cr2O7

Reported statistics and error estimates:

The differences in means of control and sample were estimated by the test t-test for independent groups at a 95% confidence level, all individual replicates were used. Statistically significant differences are for p < 0.05.

Concentration of test Substance: spectrophotometric determination at 209 nm after centrifugation of the sample (1395 g, 5 min) – start of the test 102.5 mg/L , the end of the test 102.2 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

The median effective concentration (EC50) for the test substance, in a freshwater algae Desmodesmus subspicatus was determined to be >100 mg/L on the basis of effects on growth rate in a 72 hour study.

Executive summary:

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance according to OECD Guideline 201.

A limit test at sample concentration of 100 mg/L was performed. Effects on the growth rate of the organism were studied.The median effective concentration (EC50) for the test substance, test material, in Desmodesmus subspicatus was determined to be >100 mg/L. Based on this EC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that thet test substance does not exhibit toxicity to aquatic algae (Desmodesmus subspicatus).

Description of key information

Toxicity to aquatic algae and cyanobacteria:

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance according to OECD Guideline 201.

A limit test at sample concentration of 100 mg/L was performed. Effects on the growth rate of the organism were studied.The median effective concentration (EC50) for the test substance, test material, in Desmodesmus subspicatus was determined to be >100 mg/L. Based on this EC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that thet test substancedoes not exhibit toxicity to aquatic algae (Desmodesmus subspicatus).

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

Additional information

Various studies for the target chemical were reviewed to summarize the following information for the toxicity to aquatic algae endpoint:

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance according to OECD Guideline 201. A limit test at sample concentration of 100 mg/L was performed. Effects on the growth rate of the organism were studied. The median effective concentration (EC50) for the test substance, test material, in Desmodesmus subspicatus was determined to be >100 mg/L. Based on this EC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that the test substance does not exhibit toxicity to aquatic algae (Desmodesmus subspicatus).

 

Another study was described in authoritative database. Growth Inhibition of test material to Alga (Pseudokirchneriella subcapitata) was observed for 72 h . The Initial cells density precultured algae was 5000 cells/mL etc.), cell aggregation or any difference from the control were not observed for concentrations 1 - 3. On the other hand, enlargement of cell volume (swelling) was found in some cells for concentrations 4 and 5. The effect concentration (EC50) for test material on Pseudokirchneriella subcapitata was observed to be 641 mg/l 95 % CL: 572 - 719 mg/L.Based on this EC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that thet test substance does not exhibit toxicity to aquatic algae.

 

The study was designed to assess the toxic effects of the test compound on the green alga Chlorella vulgaris. Test was conducted in compliance with the OECD guideline 201 (Alga, Growth Inhibition Test). Test was carried out in 100mL conical flasks which were carefully autoclaved and sterilized. The test solution in each of these test vessels was kept constant which is 60 ml so that a sufficient amount of head space was left. The test substance was prepared by adding 50 mg of test item in 250 ml of BBM to get the final concentration of 200mg/L. This stock solution was kept for stirring/ sonication for 0 minutes to obtain a homogenous solution for the experiment. The test concentrations6.25mg/l, 12.5mg/l, 25mg/l, 50mg/l and 100mg/l,200mg/l were chosen according to the available data of the test item. The concentrations chosen were set up to the water solubility limit. The remaining test solutions were prepared by dilution from the above stock solution. For the assessment of algal growth, the test was conducted in replicates. The control flask was maintained in triplicates as recommended in the OECD guideline and the test concentration were selected in geometric series which were maintained in duplicates. To obtain a quantitative concentration-response relationship by regression analysis, a linearizing transformation of the response data into probit was performed. Using the same, effective concentration (EC) were determined. Algal growth was calculated daily by counting the cells microscopically with the help of haemocytometer. For microscopic observations the cultures were observed daily with the help of a microscope to verify a normal and healthy appearance of the algal culture and also to observe any abnormal appearance of the algae (as may be caused by the exposure of the test item). Apart from this, the cell count of each test vessel was also noted with the help of a microscope and haemocytometer. By spectrophotometer the absorbance values of each test vessel and control vessel was noted at 680nm.The BBM was taken as blank for both control and test vessels. The absorbance value of each vessel was in line with the average specific growth rate. As per OECD 201, the biomass in the control cultures should have increased exponentially by a factor of at least 16 within the 72 hr test period. This corresponds to a specific growth rate of 0.92 per day. Thus, the observed specific growth rate in the control cultures during the experiment was 0.358 per day. Secondly the mean coefficient of variation for section by section specific growth rates (days 0-1, 1-2 & 2-3, for 72 hr tests) in the control cultures must not exceed 35%. Thus, the observed mean coefficient of variation in the control cultures during the experiment was 33.42%. Thirdly the coefficient of variation of average specific growth rates during the whole test period in replicate control cultures must not exceed 10%. Thus, the observed coefficient of variation of average specific growth rates during the experiment in control cultures was 8.26%. Hence, the test is considered valid as per OECD guideline, 201. After 72 hours of exposure to test item to various nominal test concentrations, EC50 was determine to be 9.836mg/l graphically and through probit analysis. Based on the EC50, it can be concluded that the chemical was and can be consider to be classified as aquatic acute 2 as per the CLP classification criteria.

Another study was described in peer reviewed journal. Toxicity to algae test material was performed in Scendesmus Obliquus Algae to observe the toxicity of Freshwater green algae Scendesmus Obliquus was obtained from algae laboratory of the girls college, Ainshams University. The algae was taken and transferred into a series of 100 ml cotton stoppered Erlenmeyer flasks containing 50ml modified Bold' s basal medium then chemical added at different concentrations as 0, 0.1, 0.3, 0.5, 1.0, 1.5, 2.0, 5, 10,15 and 20 mg/l and growth was monitored by chlorophyll-a content estimation using a method describe by APHA. Based on the experiment the EC 50 value for test material for toxicity to algae was determined to be 1.2 mg/l after 72 hrs.

Since, Data from study report and peer reviewed journal suggests that the test substance is not toxic to aquatic algae and cyanobacteria, hence test material can be considered to be not classified as per CLP criteria.