3,5-xylidine

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23.01.1990 - 25.01.1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Qualifier:

according to guideline

Guideline:

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

"Gute Laborparxis" 1983

Analytical monitoring:

no

Test organisms (species):

activated sludge

Details on inoculum:

- Laboratory culture: yes
- Name and location of sewage treatment plant where inoculum was collected: 10L from OECD lab, 19.01.1990
- Pretreatment: no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Nominal and measured concentrations:

100, 180, 320, 560, 1000 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-dichlorphenol

Duration:

3 h

Dose descriptor:

EC50

Remarks:

Respiration inhibition

Effect conc.:

914 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Test item concentration (mg/L)	Respiration rate (mg/L*h)	Inhibition (%)
100	24	7
180	24	7
320	24	7
560	18	31
1000	10	60

Validity criteria fulfilled:

yes

Remarks:

The validity of the test was checked by means of a graphical evaluation of the reference substance.

Conclusions:

The EC50(3h) on microorganisms for the test substance was 914 mg/L (nominal).

Executive summary:

The test item was assessed in an test on toxicity to bacteria with 3,5-Xylidine according to ISO 8192-1986 (E), similar to OECD 209 and following GLP. Activated sludge was incubated for 3h to nominal test concentrations of 100, 180, 320, 560, 1000 mg/L- The respration rate was measured. The EC50(3h) on microorganisms for the test substance was 914 mg/L (nominal).

Description of key information

ISO 8192-1986 (E), similar to OECD 209, activated sludge, GLP, nominal test concentrations of 100, 180, 320, 560, 1000 mg/L- The EC50(3h) 914 mg/L (nominal).

Key value for chemical safety assessment

EC50 for microorganisms:

914 mg/L