Chlorocyclopentane

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-10-24 to 2018-11-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: ISO International Standard 10634 "Water Quality - Guidance for the preparation and treatment of poorly water-soluble organic compounds for the subsequent evaluation of their biodegradability in an aqueous medium" (1995).

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Chlorocyclopentane

EC Number:

213-212-5

EC Name:

Chlorocyclopentane

Cas Number:

930-28-9

Molecular formula:

C5H9Cl

IUPAC Name:

chlorocyclopentane

Test material form:

liquid

Details on test material:

- Name as stated in the report: JNJ-64259884-AAA (Cyclopentylchloride)
- Physical state: Liquid
- Appearance: clear to light yellow liquid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Analytical purity: 100.0%
- Source and lot/batch No.of test material: M16CD0746
- Expiration date of the lot/batch: 2019-01-28 (retest date)

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature
- Solubility in water: 0.8 g/L

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source: Municipal sewage treatment plant receiving predominantly domestic sewage, 'Waterschap Aa en Maas', 's-Hertogenbosch, The Netherlands.
- Storage conditions: Sludge was kept under continuous aeration until further treatment
- Preparation of inoculum for exposure: Before use, the sludge was coarsely sieved (1 mm) and washed with mineral medium.After treatment, the concentration of
suspended solids (SS) was determined to be 5.4 g/L in the concentrated sludge as used for the test. The sludge was used as inoculum at a concentration of 0.9 mL per litre of mineral medium, leading to a final concentration SS of 5 mg/L
- Pretreatment: no
- Concentration of sludge: The concentration of suspended solids was determined to be 5.4 g/L in the concentrated sludge.
- Water filtered: Tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

37.4 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

12 mg/L

Based on:

TOC

Initial test substance concentration 3

Initial conc.:

80 mg/L

Based on:

ThOD

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: test water prepared according to test guidelines, analytical grade salts dissolved in tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon.
* mineral stock solution A: 8.5 g KH2PO4, 21.75 g K2HPO4, 67.20 g Na2HPO4.12H2O, 0.5 gNH4Cl dissolved in 1 L Milli-Q water, pH 7.4 ± 0.2
* mineral stock solution B: 22.50 g MgSO4.7H2O dissolved in 1 L Milli-Q water
* mineral stock solution C: 36.4 g CaCl2.2H2O dissolved in 1 L Milli-Q water
* mineral stock solution D: 0.25 g FeCl3.6H2O dissolved in 1 L Milli-Q water
* Final test medium: 10 mL of solution A and 1 mL of solutions B, C and D per L of test medium
- Additional substrate: no
- Test temperature: 22-23°C
- pH: 7.3-8.2, measured prior to testing in each test flask before addition of inoculum, and again in each test flask at the end of the incubation period
- pH adjusted: no
- Aeration of dilution water: The test solutions were continuously aerated and stirred during the test.
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 500 mL brown coloured glass bottles
- Number of culture flasks/concentration: 2
* test substance and inoculum: 2 replicates
* inoculum blank: 2 replicates
* procedure control: 1 replicate
* toxicity control: 1 replicate
- Experiemntal CO2 production: The CO2 produced in each test bottle reacted with the CO2 absorbent in the rubber gaskets. As gaseous O2 was converted into gaseous CO2 that was absorbed, the gas pressure in the test system slowly decreased. This decrease in air pressure was measured by the respirometer heads and automatically converted into oxygen consumption (mg O2/L).
- Theoretical Oxygen Demand: The ThOD was calculated from the molecular formula.
- respirometer: Lovibond BD600-GLP manometric respirometry system, equipped with an inductive stirring system.

SAMPLING
- Sampling frequency: Measurements were recorded on day 0-4-7-11-14-18-21-25-28. Measurement of the procedure and toxicity control lasted until Day 14.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, two replicates with only inoculum
- Toxicity control: yes, one replicate with test item, reference substance, and inoculum
- Procedure control: yes, 1 replicate with reference item and inoculum

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

Test performance:

- In the toxicity control more than 25 % degradation occurred within 14 days (60% based on ThOD). Therefore, the test substance was assumed to be not inhibitory on microbial activity.
- The difference of duplicate values for %-degradation of the test item was always less than 20 (≤12%).

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

ca. 47

Sampling time:

28 d

Remarks on result:

other: mean of test bottle A and B

Details on results:

The criterion for ready biodegradability (at least 60% biodegradation within 10 days of biodegradation exceeding 10%) was not met.
The ThOD of JNJ-64259884-AAA (Cyclopentylchloride) was calculated to be 2.14 mg O2/mg.
The ThOD of sodium acetate was calculated to be 0.78 mg O2/mg.
The relative biodegradation values calculated from the measurements performed during the test period revealed 53% and 41% biodegradation of JNJ-64259884-AAA (Cyclopentylchloride) (based on ThOD), for the duplicate bottles tested.
In the toxicity control, more than 25% biodegradation occurred within 14 days (60%, based on ThOD) at the tested target concentration of 37 mg/L, corresponding to 12 mg TOC/L. Therefore, the test item was assumed not to inhibit microbial activity.

BOD5 / COD results

Results with reference substance:

The positive control item was biodegraded by at least 60% (89%) within 14 days, confirming suitability of the activated sludge.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

A 28-d ready biodegradability test (OECD 301F, Manometric Respirometry test) using unadapted activated sludge from a predominantly domestic waste water treatment plant indicated that cyclopentylchloride was not readily biodegradable under the conditions of the test (initial concentration 37.4 mg/L). The test substance showed only 53% and 41% biodegradation (test bottle A and B, respectively, based on % ThCO2). The test substance did not inhibit microbial activity at the concentration used in the test. The results of the test can be considered reliable without restriction.