5H-1,2-oxathiole 2,2-dioxide

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
Ambient(21 to 29℃)
- Solubility and stability of the test material in the solvent/vehicle and the exposure medium:
soluble and stable


TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing (e.g. warming, grinding):
no
- Preliminary purification step (if any):
- Final concentration of a dissolved solid, stock liquid or gel:
not specified

Analytical monitoring:

no

Vehicle:

yes

Remarks:

deionised water

Test organisms (species):

activated sludge

Details on inoculum:

- Laboratory culture:
not specified
- Name and location of sewage treatment plant where inoculum was collected:
wastewater treatment plant of Siddaganaga Institute of Technology, Tumkur-572103 receiving predominantly domestic sewage.
- Method of cultivation:
not specified
- Preparation of inoculum for exposure:
The sludge was washed and centrifuged for a period of 10 minutes at 10,000 m/s2 to produce a clear supernatant and pellet of sewage solids. The supernatant liquid was discarded and the sludge re-suspended in deionized water with shaking and the washwater was removed by re-centrifuging and discarding again. A known quantity of the activated sludge was suspended in required quantity of deionized water. The dry mass of the suspended solids were determined. The mass of a known volume of the suspended sludge in deionized water was determined to obtain the required sludge stock solids concentration of 2 to 4 g/L.

- Initial biomass concentration:
3.5 g/L

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

20 ± 2°C.

Dissolved oxygen:

above 60 – 70% saturation

Details on test conditions:

TEST SYSTEM
- Test vessel:
beaker
- Material, size, headspace, fill volume:
The test vessel 1000 mL beaker to contain 500 mL of reaction mixture.
- No. of vessels per concentration (replicates):
5
- No. of vessels per control (replicates):
6
- No. of vessels per vehicle control (replicates):
0
- No. of vessels per abiotic control (replicates):
0
- Sludge concentration (weight of dry solids per volume):
1500 mg/L

- Nutrients provided for bacteria:
Urea, Sodium chloride, CaCl2.2H2O, MgSO4.7H2O, K2HPO4.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
TEST CONCENTRATIONS
- Spacing factor for test concentrations:
3.16
- Range finding study
- Test concentrations:
10 mg/L, 100 mg/L and 1000 mg/L
- Results used to determine the conditions for the definitive study:
0%, 7.26 % and 27.36% respectively.

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Key result

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Key result

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

140.16 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Details on results:

The NOEC of the test item is 10 mg/L, the test item is non-toxic at the concentration to the activated sludge of a sewage treatment plant. The EC10, EC20 and EC50 of the test item are 140.16 mg/L, 448.59 mg/L and >1000 mg/L respectively.

Results with reference substance (positive control):

inhibition effects of reference substance 3,5-dichlorophenol at concentration of 2, 6, 36 mg/L are 2.7%, 11.98% and 81.18%.
Results meet the criteria.

Validity criteria fulfilled:

yes

Conclusions:

1,3-Propene Sultone is non- toxic at the concentration of 10 mg/L to the activated sludge of a sewage treatment plant.
The NOEC, EC10, EC20 and EC50 of the test item are 10mg/L, 140.16 mg/L, 448.59 mg/L and >1000 mg/L respectively.

Executive summary:

Activated Sludge Respiration Inhibition Test was conducted according to OECD Guideline No. 209 carried out with the test item1,3-Propene Sultone.

 

Test system was activated sludge of the treatment plant. The main test was carried out under the test conditions with the test item concentrations 10 mg/L, 31.6 mg/L,         100 mg/L, 316 mg/L, and 1000 mg/L.

The blank controls (without the test item or reference substance) mean oxygen uptake rate was less than 20 mg oxygen per one gram of activated sludge (dry weight of suspended solids) in an hour. The coefficients of variation (RSD) of oxygen uptake rate in Inoculum Blank with six replicates wereless than 30% at the end of main test.

 

The respiration rates of the inoculum blank, reference substance and test item replicates were measured after the exposure period of three hours, and the inhibitory effects of the test item and reference substance were determined in comparison to the inoculum blank respiration rates. 

 

In order to check the activity of the test system and the test conditions a reference substance was carried out with 3, 5-dichlorophenol and the reference toxicity was determined. The EC50-value for the reference substance was found to lie between the 2 to 25 mg/L.

 

The mean inhibition of respiration for the test item1,3-Propene Sultonewith five replicates at the concentrations of 10 mg/L, 31.6 mg/L, 100 mg/L, 316 mg/L, and 1000 mg/L were -2.71%, 3.24%, 7.49%, 18.62% and 28.04% respectively.

 

(I)Group     (J) Group	Mean Difference (I-J)	Std. Error	Sig.	95% Confidence        Interval
				Lower Bound
T1                  T0	-2.70800	.33778	1.000	-3.5097
T2                  T0	3.24000*	.33778	.000	2.4383
T3                            T0	7.48800*	.33778	.000	6.6863
T4                             T0	18.61600*	.33778	.000	17.8143
T5                  T0	28.03600*	.33778	.000	27.2343

*The mean difference isstatisticallysignificant effect at p 0.05 level usingANOVA, Dunnett t-tests methodtreat one group as a control, and compares all other groups against it.

 

The EC-Values with 95% Confidence Interval of the test item were listed below table.

 

Details	EC-values	Confidence Interval P = 95 [%]
		Lower Limit	Upper Limit
NOEC**	10 mg/L	-	-
EC10	140.16 mg/L	83.98 mg/L	233.93 mg/L
EC20	448.59 mg/L	283.69 mg/L	709.35 mg/L
EC50	> 1000 mg/L	-	-

The EC10 and EC20 were calculated using Probit analysis. **No statistically significant effect (p 0.05), ANOVA, Dunnett t-tests Method.

 

The NOEC of the test item is 10 mg/L, the test item is non-toxic at the concentration to the activated sludge of a sewage treatment plant. The EC10, EC20 and EC 50 of the test item are 140.16 mg/L, 448.59 mg/L and >1000 mg/L respectively.

 

Conclusion

 1,3-Propene Sultoneis non - toxic at the concentration of 10 mg/L to the activated sludge of a sewage treatment plant. The EC10, EC20 and EC50 of the test item are 140.16 mg/L, 448.59 mg/L and >1000 mg/L respectively.

Description of key information

1,3-Propene Sultone is non- toxic at the concentration of 10 mg/L to the activated sludge of a sewage treatment plant.

The NOEC, EC10, EC20 and EC50 of the test item are 10mg/L, 140.16 mg/L, 448.59 mg/L and >1000 mg/L respectively.

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

EC10 or NOEC for microorganisms:

10 mg/L