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Ecotoxicological information

Toxicity to microorganisms

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Reference
Endpoint:
toxicity to microorganisms
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: No GLP, no analytical monitoring
Principles of method if other than guideline:
toxicity testing to Tetrahymena pyriformis according to Schultz et al. (1997); TERATOX assay
A short-term, static protocol using the common freshwater ciliate Tetrahymena  pyriformis (strain GL-C) is reported.  The 50% impairment growth 
concentration (IGC50) is the endpoint of choice.
GLP compliance:
no
Analytical monitoring:
no
Vehicle:
no
Test organisms (species):
Tetrahymena pyriformis
Details on inoculum:
- Source: Test organisms was obtained from Jorgen Larsen, Environmental Technology, Danish Technological Insitute (P.O. Box 141, DK-2630, Taasturp, Denmark).
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
40 h
Test temperature:
27 ±1 °C
Details on test conditions:
A short-term, static protocol using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C) is reported. The 50% impairment growth 
concentration (IGC50) is the endpoint of choice. Cultures are reared in 50 mL of a semidefined medium in 250 mL Erlenmeyer flasks. Definitive test 
replicates consist of six to ten different concentrations of each test material with duplicate flasks. Duplicate flasks are inoculated to an initial density of approx. 2500 cells/mL with log-growth-phase ciliates. Following 40 h of incubation at 27 ±1 °C, population density is quantified 
spectrophotometrically at 540 nm and 50% effect levels are determined by Probit Analysis of Statistical Analysis system software.

Toxicity was assessed in the 2-day Tetrahymena pyriformis (strain GL-C)  population growth impairment assay. The test followed the protocol  
described by Schultz (1997).

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed (foam stoppered)
- Material, size, headspace, fill volume: 50 mL of a semidefined medium in 250 mL Erlenmeyer flasks
- No. of organisms per vessel: 2500 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 2
Duration:
40 h
Dose descriptor:
other: IGC50
Effect conc.:
13.93 mg/L
Remarks on result:
other: Original value: log(IGC50 E-1): 1.087 mM
Conclusions:
In a short-term, static study using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C) the 50% impairment growth concentration (IGC50) is 19.93 mg/L. 
Executive summary:

In a short-term, static study using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C) the 50% impairment growth concentration (IGC50) is 19.93 mg/L.

Description of key information

In a short-term, static study using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C) the 50% impairment growth concentration (IGC50) is 19.93 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:
19.93 mg/L

Additional information

In a short-term, static study using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C) the 50% impairment growth concentration (IGC50) is 19.93 mg/L.