Styrene

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to microorganisms, other

Remarks:

cell inhibition

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

no guideline followed

Principles of method if other than guideline:

Preparation of bacteria stock cultures in agar vials. Stock cultures incubated for 24 h at 25°C. Continuous preparation of new stock cultures in a one week interval. For the preparation of the bacteria suspension bacteria are washed away by aid of sterile NaCl-solution and further diluted with NaCl-solution. Adjustment of extinction value to formacine-standard suspension. Preparation of different concentrations of the test solution. Preparation of final test solution: 80 mL test solution of respective concentrations, 5 mL stock solution I, 5 mL stock solution II and 10 mL bacteria suspension. 3 replicates of each concentration. Incubation of flaks for 16 hours at 25°C. At end of incubation period measurement of extinction of monochromatic radiation.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Neutralisation of test solution (addition of acid or base). Preparation of dilution series with sterile, destilled water: starting concentration 160 mL test solution, lower concenrations prepared by a spacing factor of 2. All concentrations for final test are filled up to a volume of 100 mL by adding 80 mL test solution, 5 mL of the stock solution I, 5 mL of the stock solution II and 10 mL of the bacteria suspension
- Controls: same (exception: for final test 10 mL NaCl-solution)

Test organisms (species):

Pseudomonas putida

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

16 h

Test temperature:

25°C

pH:

7.0

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks with cotton-filled plastic caps
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: glass, with headspace, 300 mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 1


TEST MEDIUM / WATER PARAMETERS
- Culture medium different from test medium: Bacteria grown on agar culture medium and tested in test solution


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Toxic limit concentration mg/L [exticntion of monochromatic radiation]

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2

Reference substance (positive control):

no

Duration:

16 h

Dose descriptor:

NOEC

Effect conc.:

72 mg/L

Conc. based on:

test mat.

Basis for effect:

other: starting inhibition effect on cell proliferation

Executive summary:

Styrene was testet for possible toxicological effects in an test on Pseudomonas putida. The NOEC after 16h was found to be 72 mg/L. 

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 June 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Principles of method if other than guideline:

Activated sludge, respiration inhibition test, 30 min

GLP compliance:

not specified

Analytical monitoring:

not specified

Details on test solutions:

- stock solution: for a concentration of 1200 mg/L: 0.3 g per vessel; for a concentration of 100 mg/L: 0.025 g
- synthetic medium: 8 mL per vessel
- inoculum: 50 mL per vessel
- dry substance: 1 g/L per vessel
- vessel volume: 250 mL

Test organisms (species):

activated sludge of a predominantly domestic sewage

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 min

Test temperature:

20 - 25°C

Nominal and measured concentrations:

100, 1200 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- No. of vessels per concentration (replicates): 1

Reference substance (positive control):

not specified

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

ca. 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

30 min

Dose descriptor:

other: EC20

Effect conc.:

ca. 140 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Respiration rate (mg/l.h): 8 (at concentration of 1200 mg/L), 30 (at concentration of 100 mg/L).

Executive summary:

Styrene was testet for possible toxicological effects in an test on activated sludge of a predominantly domestic sewage. The EC50 after 30 min was found to be ca. 500 mg/L. 

Description of key information

Styrene was testet for possible toxicological effects in an acute test on activated sludge. The EC50 after 30 min was found to be 500 mg/L. 

Key value for chemical safety assessment

EC50 for microorganisms:

500 mg/L

Additional information

In short term respiration test conducted with activated sludge from municipal, non-adapted sewage treatment plant. resulted in an EC50 (30 min) and EC20 (30 min) of approx. 500 and 140 mg/l, respectively (BASF AG, 1988). The toxicity treshold (taken equivalent to NOEC) for Pseudomonas putida after an exposure time of 16 hours was 72 mg/l (Bringmann & Kühn, 1977). Other cell multiplication tests conducted with bacteria and protozoa (Bringmann & Kühn, 1973,1978 ,1980 and 1982, Qureshi, 1982, Andreeva, 2019, Mosafa, 2016) indicate similar (or lower) sensitivity.