4-phenoxyphenol

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:

2018

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

Deviations:

yes

Remarks:

An abiotic Control for the reference item was performed during this study although it was not planned in the study plan.

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Batch 20180329 (Source Lead)
- Expiration date of the lot/batch: March 2019
- Purity test date: March 2018

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: romm temperature 20 +/-10°C
- Stability under test conditions: stable
- Solubility in water : 0.19 to 0.26 g/L

Analytical monitoring:

no

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION:
- Method: directly diluted
- Controls: Yes
- Chemical name of vehicle : osmosed water
- Concentration of vehicle in test medium : 10 - 40 - 160 - 640 and 2560 mg/L
- Evidence of undissolved material: the test item is poorly soluble in water

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Laboratory culture: FCBA
- Name and location of sewage treatment plant where inoculum was collected: STEP de Lille, 33290 BLANQUEFORT - FRANCE
- Method of cultivation: A filtration through a fine sieve (around 1 mm) was performed in order to remove coarse particles. After removal of any coarse particles, the sludge was washed by decantation in osmosed water and test medium ( 50/50 (v/v) to adjust concentration of dry extract around 3 g/L. The activated sludge was continuously aerated until usage in the test and fed daily with 50 mL/L synthetic sewage feed for one or two additional days.
- Test medium : mineral mediium (Na2HPO4, 2H2O, K2HPO4, NH4Cl, KH2PO4, CCl2, 2H2O, MGSO4, 7H2O, FeCl3, 6H20)
- Initial biomass concentration: 1.45 g suspended solids/L in this test

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 d

Hardness:

No data

Test temperature:

20 +/-2°C

pH:

End of the test : 8.2 to 8.6

Salinity:

Not relevant

Conductivity:

Not relevant

Nominal and measured concentrations:

Nominal : 10 - 40 - 160 - 640 and 2560 mg/L

Details on test conditions:

The test was carried out into 1000 mL glass flasks containing 500 mL as below:
- 16.0 ml synthetic sewage feed (Peptone, Meat Extract, Ura, NCl, CaCl2-2H2O, MgSO4-7H20, K2HPO4, ultrapure water)
- Adequate weighing of test item
- osmosed water (final volume: 500 mL)
- 250 mL of sludge suspension

Replicates: Six replicates for controls (Control a to Control f)
Two replicates for abiotic controls
Three replicates (a, b and c) per treatment (1 to 5) for the test item
One replicate per treatment for the reference item (3,5 DCP)

The concentrations for the 3,5 DCP were : 0.5 – 1.6 – 5.1 – 16.40 and 52.4 mg/L

At the start of the test, the first control (Control a) was prepared and covered with parafilm. Then every 10 -15 minutes the others flasks were prepared in turn in the same conditions. Finally, the last control (Control f) was prepared.
All suspensions were aerated with purified air (0.5 to 1 L/min), and stirred during 3 hours at 20 ± 2°C. Then, each suspension was poured into Karlsruher flask (following the order preparation). The Oxygen was measured every minute, during 10 minutes, with a Dissolved Oxygen Sensor (WTW StirrOx G) integrated Stirrer, inserted into the Karlsruher flask

EFFECT PARAMETERS MEASURED : Activated sludge respiration inhibition, measured as oxygen consumption rate (dissolved oxygen concentration)

Reference substance (positive control):

yes

Remarks:

3,5 dichlorophenol

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 43.2 - < 296.6 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.:

ca. 165.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

ca. 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Duration:

3 h

Dose descriptor:

LOEC

Effect conc.:

ca. 40 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Details on results:

-

Results with reference substance (positive control):

- Results with reference substance valid : Yes
- Relevant effects levels : EC50 : 13.7 mg/L ; oxygen uptake in the control : 38.8 mg O2/ g sludge/h ; Coefficient of varation of O2 : 0.0 to 14.6%

  O2 consumption and inhibition

Treatment	Name	O2consumption in mg O2/(L*h)	% inhibition	pH (end of the test)
Inoculum Control	Control a	51.00	/	8.4
	Control b	52.50	/	8.4
	Control c	61.50	/	8.3
	Control d	60.00	/	8.2
	Control e	57.60	/	8.2
	Control f	55.20	/	8.3
Abiotic Control reference item	Abiotic Control 3,5 DCP	/	/	7.0
Reference Item	3,5 DCP Conc 1	55.5	1.42	8.3
	3,5 DCP Conc 2	54.0	4.09	8.4
	3,5 DCP Conc 3	48.0	14.74	8.4
	3,5 DCP Conc 4	22.7	59.68	8.4
	3,5 DCP Conc 5	7.5	85.79	8.4
Abiotic Control Test item	Abiotic Control Test item a	/	/	7.0
Test Item	1a	62.00	- 10.1	8.2
	1b	62.00	- 10.1	8.2
	1c	54.00	4.1	8.3
	2a	42.00	25.4	8.3
	2b	43.00	23.6	8.3
	2c	36.00	36.1	8.4
	3a	8.00	85.8	8.4
	3b	3.43	93.9	8.5
	3c	3.33	94.1	8.4
	4a	0.00	100.0	8.6
	4b	0.67	98.8	8.6
	4c	0.00	100.0	8.6
	5a	0.67	98.8	8.6
	5b	0.00	100.0	8.6
	5c	0.67	98.8	8.6
Abiotic Test item	Abiotic Test item b	/	/	7.0

Validity criteria fulfilled:

yes

Conclusions:

This study was performed using five concentrations, ranging from 10 to 2560 mg/L nominal concentrations. The dry matter of the activated sludge was determined as 2.9 g suspended solids/L, giving a concentration of 1.45 g suspended solids/L in this test. The validity criteria for OECD 209 were successful. And the nominal concentrations of 4-PhenoxyPhenol are :
- CE50-3h = 165.4 mg/L [43.2 - 296.6]
- NOEC = 10 mg/L
- LOEC = 40 mg/L

Executive summary:

An OECD 209 was performed on 4 -PhenoxyPhenol using five concentrations, ranging from 10 to 2560 mg/L nominal concentrations. The dry matter of the activated sludge was determined as 2.9 g suspended solids/L, giving a concentration of 1.45 g suspended solids/L in this test. The validity criteria for OECD 209 were successful. And the nominal concentrations of 4-PhenoxyPhenol are :

• CE50-3h = 165.4 mg/L [43.2 - 296.6]
• NOEC = 10 mg/L
• LOEC = 40 mg/L

Description of key information

An OECD 209 was performed on 4 -PhenoxyPhenol using five concentrations, ranging from 10 to 2560 mg/L nominal concentrations. The dry matter of the activated sludge was determined as 2.9 g suspended solids/L, giving a concentration of 1.45 g suspended solids/L in this test. The validity criteria for OECD 209 were successful. And the nominal concentrations of 4-PhenoxyPhenol are :

• CE50-3h = 165.4 mg/L [43.2 - 296.6]
• NOEC = 10 mg/L
• LOEC = 40 mg/L

Key value for chemical safety assessment

EC50 for microorganisms:

165.4 mg/L

EC10 or NOEC for microorganisms:

10 mg/L