Santicizer P1400

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 with acceptable restrictions

Justification for type of information:

A discussion and report on the read across strategy is provided as an attachment in Section 13 of the dossier.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Principles of method if other than guideline:

Increased evaluation of pH, oxygen consumption, and measurement of respiration rate.

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Polyadd Limited (c/o H.I.G. European Capital Partners LLP 25 St. George Street London, W1S 1FS, UNITED KINGDOM); Batch no. 0900
- Expiration date of the lot/batch: 2016-10-22
- Purity test date: 2015-10-22
- Purity: 98.8

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature in the dark

FORM AS APPLIED IN THE TEST (if different from that of starting material): clear colorless liquid

Analytical monitoring:

yes

Details on sampling:

Observations and measurements were conducted at 0 hours, 30 minutes, and 3 hours.

Details on test solutions:

Nominal amounts of test item (5, 50 and 500 mg (in triplicate)) were each separately dispersed in approximately 200 mL of deionized reverse osmosis water and subjected to ultrasonication for approximately 15 minutes followed by magnetic stirring for 24 hours, at temperatures of between 20 °C and 21 °C, in order to maximize the dissolved test item concentration. All test vessels were shielded from the light during mixing. Synthetic sewage (16 mL), activated sewage sludge (250 mL) and water were added to a final volume of 500 mL to give the required concentrations of 10, 100 and 1000 mg/L (3 replicates).

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

A mixed population of activated sewage sludge micro-organisms was obtained on 4 December 2015 from the aeration stage of the Severn Trent Water Plc sewage treatment plant at Loughborough, Leicestershire, UK which treats predominantly domestic sewage.

Test type:

static

Water media type:

freshwater

Total exposure duration:

3 h

Test temperature:

The test was conducted in a temperature controlled room maintatined at 20 ºC.

pH:

The pH ranged from 7.5-7.7 during the testing of the test item.

Dissolved oxygen:

Initial oxygen readings for the test were between 4.1 and 5.6 mg O2/L

Nominal and measured concentrations:

Nominal concentrations of 10, 100, and 1000 mg/L of the test item were tested.

Details on test conditions:

At time "0" 16 mL of synthetic sewage was diluted to 250 mL with water and 250 mL of inoculum added in a 500 mL conical flask (first control). The mixture was aerated with clean, oil-free compressed air via narrow bore glass tubes at a rate of 0.5 to 1.0 liter per minute. Thereafter, at 15 minute intervals the procedure was repeated for the second control followed by the reference item vessels with appropriate amounts of the reference item being added

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

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:

other: inhibition of sludge respiration rate

Key result

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

After 3 hours an EC50 of 12mg/L was achieved.

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test item on the respiration of activated sewage sludge micro-organisms gave a 3-Hour EC50 value of greater than 1000 mg/L. The No Observed Effect Concentration (NOEC) after 3 hours exposure was 1000 mg/L.

Executive summary:

The effect of the test item on the respiration of activated sewage sludge micro-organisms was assessed following themethods outlined n the OECD 209 guideline. A positive control was carried out using 3-5,dichlorophenol as a reference item. Following the testing a 3-Hour EC50 value of greater than 1000 mg/L and a No Observed Effect Concentration (NOEC) after 3 hours exposure was 1000 mg/L was determined for the test item. The reference item was determined to have an EC50 of 12mg/L. All validation criteria for the testing were fufilled.

Description of key information

The effect of the test item on the respiration of activated sewage sludge micro-organisms was a 3-Hour EC50 value of greater than 1000 mg/L and a No

Observed Effect Concentration (NOEC) after 3 hours exposure was 1000 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

EC10 or NOEC for microorganisms:

1 000 mg/L

Additional information

The effect of the test item on the respiration of activated sewage sludge micro-organisms was assessed following themethods outlined n the OECD 209 guideline. A positive control was carried out using 3-5,dichlorophenol as a reference item. Following the testing a 3-Hour EC50 value of greater than 1000 mg/L and a No Observed Effect Concentration (NOEC) after 3 hours exposure was 1000 mg/L was determined for the test item. The reference item was determined to have an EC50 of 12mg/L. All validation criteria for the testing were fufilled.