Reaction mass of (Z)-1-chloro-1-propene and 2-chloropropane and 2-chloropropene

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:

September 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study performed according to OECD guideline 301D

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-chloropropene

EC Number:

209-187-5

EC Name:

2-chloropropene

Cas Number:

557-98-2

Molecular formula:

C3H5Cl

IUPAC Name:

2-chloroprop-1-ene

Constituent 2

Reference substance name:

2-chloropropane

EC Number:

200-858-8

EC Name:

2-chloropropane

Cas Number:

75-29-6

Molecular formula:

C3H7Cl

IUPAC Name:

2-chloropropane

Constituent 3

Reference substance name:

1-chloropropene

EC Number:

209-675-8

EC Name:

1-chloropropene

Cas Number:

590-21-6

IUPAC Name:

1-chloroprop-1-ene

Details on test material:

Identification Reaction mass containing mainly 2-chloropropene
Molecular formula C3H5Cl
Molecular weight 76.53
CAS Number 557-98-2
Description Clear light yellow to brown liquid (determined at NOTOX)
Batch RBA100301A
Purity Minimum 60.0%
Test substance storage In refrigerator (2-8°C) in the dark
Stability under storage conditions Stable
Expiry date 08 March 2011 (allocated by NOTOX, 1 year after receipt of the test substance)

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly domestic, non-adapted

Details on inoculum:

Source The source of test organisms was secondary effluent freshly obtained from a municipal sewage treatment plant: 'Waterschap Aa en Maas', 's-Hertogenbosch, The Netherlands, receiving predominantly domestic sewage.

Treatment Secondary effluent was filtered through a coarse filter paper, the first 200 ml was discarded. The filtrate was kept aerated until inoculation.

Inoculation 4 ml filtrate of secondary effluent per litre of final volume.

Reason for selection The test has been accepted internationally (EC, OECD) for determining the 'ready' biodegradability of test substances under aerobic conditions.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

>= 2 - <= 5 mg/L

Based on:

other: nominal concentration

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Test procedure and conditions:
Test duration 28 days for the inoculum blank and test suspension
14 days for the procedure and toxicity control

Test bottles 250-300 ml BOD bottles with glass stoppers.

Milli-RO / Milli-Q water Tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon and ion-exchange cartridges (Milli-Q) (Millipore Corp., Bedford, Mass., USA).

Stock solutions of A) 8.50 g KH2PO4
mineral components 21.75 g K2HPO4
67.20 g Na2HPO4.12H2O
0.50 g NH4Cl
dissolved in 1 litre Milli-Q water, pH 7.4 + 0.2
B) 22.50 g MgSO4.7H2O dissolved in 1 litre Milli-Q water.
C) 36.40 g CaCl2.2H2O dissolved in 1 litre Milli-Q water.
D) 0.25 g FeCl3.6H2O dissolved in 1 litre Milli-Q water.

Mineral medium 1 ml of solution (A) to (D) was mixed and made up to 1 litre with Milli-RO water.

The concentration of dissolved oxygen was measured for control purposes. The mineral medium was left at test temperature to obtain a saturated solution at the start of the test.

Test set up:
- Inoculum blank Containing only inoculum (no test substance)
- Procedure control Containing reference substance and inoculum
- Test suspension Containing test substance and inoculum (applicable for both test concentrations)
- Toxicity control Containing test substance at the lowest concentration, reference substance and inoculum.

Number and groups of test bottles Individual BOD bottles were prepared for each measuring point, except that the bottle measured at the start was also measured on day 7.
Parallel groups were prepared to allow duplicate measurements of oxygen consumption at the test intervals.

Temperature The test was performed at the lower limit of the temperature range (22±2°C).

Illumination The test bottles were protected from light.

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

Preliminary study:

Theoretical Oxygen Demand:
The ThOD of Reaction mass containing mainly 2-chloropropene was calculated to be 1.69 mg O2 per mg. An overview of the calculation of the ThOD is presented in Table 1.
Table 1 Calculation of ThOD

Constituent g/kg: % w/w MF MW ThOD:
1 2-Chloropropene 760.1 76.01 C3 H5 Cl 76.53 1.673
2 2-Chloropropane 102.6 10.26 C3 H7 Cl 78.65 1.834
3 (Z) 1-Chloropropene 96.7 9.67 C3 H5 Cl 76.53 1.673
4 (E) 1-Chloropropene 27.9 2.79 C3 H5 Cl 76.53 1.673
5 3-Chloropropene 5.9 0.59 C3 H5 Cl 76.53 1.673
6 Ethylchlorid 6.8 0.68 C2 H5 Cl 64.51 1.488
1000 100 1.688

The ThOD of sodium acetate (reference substance) was calculated to be 0.78 mg O2/mg.

Test performance:

The pH values at the start of the test are given in APPENDIX I.

The temperature in the test room varied between 19.9 and 20.6°C.

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

>= -1 - <= 0

Sampling time:

28 d

Remarks on result:

other: Mean of two replicates for both concentrations (2 and 5 mg/l)

Details on results:

Biodegradation is presented in Table 2 .
The relative biodegradation values calculated from the O2 measurements performed during the test period of 28 days revealed no significant biodegradation of Reaction mass containing mainly 2-chloropropene at both concentrations.
In the toxicity control less than 25% biodegradation occurred within 14 days (maximally 22%, based on ThOD). Thus, the toxicity control showed that Reaction mass containing mainly 2-chloropropene slightly inhibited microbial activity.

BOD5 / COD results

Results with reference substance:

On day 14, the mean degradation was 21.5%.

Any other information on results incl. tables

Table2           Biodegradation percentages at different points in time

Test medium	Concentration (mg/l)	% Biodegradation after x days^1)
		0	7	14	21	28
Procedure control A^2)	2	0	65	74
Procedure control B^2)	2	0	67	71
Procedure control mean A and B	2	0	66	72
Difference between duplicate values	2	0	2	3
Test substance low A^3)	2	0	-20	-4	-1	0
Test substance low B^3)	2	0	-20	-2	0	-1
Test substance low mean A and B	2	0	-20	-3	0	0
Difference between duplicate values	2	0	0	2	1	1
Test substance high A^3)	5	0	-9	-5	1	-1
Test substance high B^3)	5	0	-8	-6	1	-1
Test substance high mean A and B	5	0	-8	-5	1	-1
Difference between duplicate values	5	0	0	0	0	0
Toxicity control A	2/2^4)	0	12	22
Toxicity control B	2/2^4)	0	11	21
Toxicity control mean A and B	2/2^4)	0	12	21
Difference between duplicate values	2/2^4)	0	2	1
^1): Calculations were performed with the mean oxygen concentrations of t=0 and the oxygen depletion as given in the Appendix.
All calculations were performed without rounding off.
^2): ThOD positive control sodium acetate: 0.78 mg O2/mg
^3): ThOD test substance: 1.69 mg O2/mg
^4): Toxicity control contains sodium acetate and test substance.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Reaction mass containing mainly 2-chloropropene was not readily biodegradable under the conditions of the closed bottle test presently performed. However, it should be noted that Reaction mass containing mainly 2-chloropropene, at a concentration of 2 mg/l, slightly inhibited microbial activity.

Executive summary:

The study procedure described in this report were based onthe OECD guideline No. 301 D, 1992.In addition, the procedures were designed to meet the test methods of theCommissionRegulation (EC) No. No. 440/2008 of,Publication No. L142,Part C.4-E and the ISO International Standard 10707, 1994.

 

Reaction mass containing mainly 2-chloropropene (minimum 60.0%) is an extremely flammableclear light yellow to brown liquid. The boiling point of the test substance is very low (around 26°C, information obtained from the sponsor).The ThOD of Reaction mass containing mainly 2-chloropropene was calculated to be 1.69 mg O₂per mg.In the closed bottle test nominal concentrations of 2 and 5 mg/l were tested.

 

The following test setup was applied:

-         Inoculum blank (only inoculum, no test substance);

-         Procedure control (sodium acetate and inoculum);

-         Test suspension (Reaction mass containing mainly 2-chloropropene and inoculum);

-         Toxicity control (sodium acetate, Reaction mass containing mainly 2-chloropropene and inoculum).

 

Preparation of the test media started with a stock solution of 100 mg/l by adding 111µl test substance to 1000 ml of mineral medium. The temperature of the test medium was 20.5°C.

Thorough mixing (21 min) was used to accelerate dissolution of the test substance in mineral medium. Exact volumes of the stock solution corresponding to the test concentrations and microbial organisms were added to the test medium.

The BOD bottles were filled with the Reaction mass containing mainly 2-chloropropene containing test medium within 15 minutes after preparation and closed with glass stoppers.

Duplicate measurements were performed at the start of the experiment (day 0) and at day 7, 14, 21 and 28.

 

The relative biodegradation values calculated from the O₂measurements performed during the test period of 28 days revealed no significant biodegradation of Reaction mass containing mainly 2-chloropropene at both concentrations.

 

The toxicity control showed that Reaction mass containing mainly 2-chloropropene slightly inhibited microbial activity.

 

Since all criteria for acceptability of the test were met, this study was considered to be valid.

 

In conclusion, Reaction mass containing mainly 2-chloropropene is designated as not readily biodegradable.