Thiosemicarbazide

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD 201

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: The Notice on the Test Method Concerning New Chemical Substances

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

not specified

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method:Test solutions were prepared by mixing a stock solution of the test substance, which was prepared by dissolving the substance in test medium.

Test organisms (species):

Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Test type:

not specified

Water media type:

not specified

Limit test:

no

Total exposure duration:

72 h

Test temperature:

21.8 - 22ºC

Nominal and measured concentrations:

100, 32, 10, 3.2, 1.0 mg/L (geometric ratio; square root of 10), control (100, 32, 9.3, 2.8, 0.79 mg/L as measured concentration)

Details on test conditions:

TEST SYSTEM
- Material, size, headspace, fill volume: 600 mL/control (100 mL/vesel), 300 mL/concentration (100 mL/vessel)
- No. of vessels per concentration (replicates):3
- No. of vessels per control (replicates):6

OTHER TEST CONDITIONS
- Light intensity and quality:92 - 94 microE/m2/s

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Measurement of biomass: cell concentration

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

ca. 2.8 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

not specified

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

ca. 19 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

not specified

Basis for effect:

growth rate

Remarks on result:

other: 95 % CL: impossible to calculate

Validity criteria fulfilled:

not specified

Conclusions:

Test item has value of EC50 (72 h) of 19 mg/L and NOEC (72 h) of 2.8 mg/L based on growth rate in 72 hours, testing to Algae.

Executive summary:

Test item was tested for the toxicity to Algae in 72 hours test, in the nominal concentration: 100, 32, 10, 3.2, 1.0 mg/L, control and (100, 32, 9.3, 2.8, 0.79 mg/L as measured concentration) at temperature of 21.8 - 22ºC. Three vessels replicates per concentration and 6 vessels replicates per control were used in this study. Test solutions were prepared by mixing a stock solution of the test substance, which was prepared by dissolving the substance in test medium. Based on available data from National instititute of technology and evaluation (NITE), test item has Effective concentration EC50 (72h) of 19 mg/L and NOEC (72h) of 2.8mg/L based on growth rate.

Description of key information

Key study: Based on available data from National instititute of technology and evaluation (NITE) test item has Effective concentration EC50 (72h) of 19 mg/L and NOEC (72h) of 2.8mg/L based on growth rate.

Key value for chemical safety assessment

EC50 for freshwater algae:

19 mg/L

EC10 or NOEC for freshwater algae:

2.8 mg/L

Additional information

Key study:OECD TG 201 and GLP principles followed.

Test item was tested for the toxicity to Algae (Pseudokirchnerella subcapitata) in the nominal concentration: 100, 32, 10, 3.2, 1.0 mg/L, control and (100, 32, 9.3, 2.8, 0.79 mg/L as measured concentration) at temperature of 21.8 - 22ºC during 72 hours.Test solutions were prepared by mixing a stock solution of the test substance, which was prepared by dissolving the substance in test medium. Based on available data from National instititute of technology and evaluation (NITE), test item has Effective concentration EC50 (72h) of 19 mg/L and NOEC (72h) of 2.8mg/L based on growth rate.