Exo-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl acrylate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

No GLP.

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adoped July 17, 1992

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Version / remarks:

of May 30, 2008 (EEC Publication No. L 142/496, May 2008)

Principles of method if other than guideline:

The biodegradation of organic compounds is determined by the determination of oxygen consumption of microorganisms using a manometric
respiratory test over a period of 28 days.

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Source of inoculum/activated sludge: Aerobic activated sludge (micro-organisms from a domestic wastewater treatment plant) was supplied by ARA Werdhölzli, Zürich, Switzerland. 30 mg/l dry matter in the final mixture

Duration of test (contact time):

28 d

Initial conc.:

39.8 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Test temperature: 22 +- 0.5 °C
- pH: 7. - 7.5




TEST SYSTEM
the respirometric activity was measured as pressure change. Because the formed carbon dioxide is adsorbed, oxygen consumtion leads to a pressure decrease which is recorded by an OxiTop® measuring head (source: WTW GmbH & Co. KG, D-82362 Weilheim, Germany).


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes, poisoned with 0.2 mM HgCl2
- Toxicity control: yes, containing inoculum + test medium + test substance + sodium benzoate as ready biodegradable reference compound (on replicate)

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

51

Sampling time:

28 d

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

9 d

Remarks on result:

other: lag phase

Parameter:

% degradation (O2 consumption)

Value:

3.9

Sampling time:

10 d

Parameter:

% degradation (O2 consumption)

Value:

34.6

Sampling time:

20 d

Results with reference substance:

Biodegradation of the reference substance sodium benzoate: Sodium benzoate was sufficiently degraded to 81.9 %after 28 days of incubation. Therefore it was concluded that the aerobic activated sludge inoculum used was suitable for the test.

Biodegradation of the toxicity control: Toxicity control containing both, isobornyl acrylate and the reference substance, 59 % biodegradation after 28 days of incubation was noted.

Therefore, the test substance showed no inhibitory effect to the aerobic activated sludge micro organisms.
Abiotic control: There was no oxygen demand in the abiotic control with isobornyl acrylate.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Isobornyl acrylate achieved 51% biodegradation in the Manometric Respirometry Test. The 10-d window was failed. Therefore, the substance is considered as not readily biodegradable according to OECD guideline 301.

Executive summary:

The biodegradability of Isobornyl acrylate exposed to microorganisms derived from activated sludge of a municipal sewage treatment plant was investigated under aerobic static exposure conditions.

The biodegradability of Isobornyl acrylate based on O₂consumption was calculated to be 51% after 28 days as compared to the theoretical oxygen demand (ThOD).

The biodegradation of Isobornyl acrylate reached 38% at the end of the 10-d window.

Biodegradation of the test substance was observed after a lag phase of about 9 days.

The procedure control sodium benzoate reached 82% biodegradation after 14 days, thus confirming suitability of inoculum and test conditions.

The calculated biodegradation based on DOC measurement reached 95% for Isobornyl acrylate and 99% for sodium benzoate. The data show that the consumed O₂was used for partial mineralization of the test compound, since the determined degradation values based on BOD were lower as compared to those based on DOC.

Isobornyl acrylate did not reach the pass level of 60% for ready biodegradability in the Manometric Respirometry Test within the 10-d window as well as after 28 days and, therefore, cannot be termed as readily biodegradable in the sense of the OECD guideline 301.

Reference 2

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental phase: 21 July 2021 – 20 September 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD 301F, GLP.

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Isobornylacrylate
IBoA
CAS-No.: 5888-33-5
Expiry Date: 6 months at max. 30°C starting delivery date
Arrival Testing facility: 21 June 2021

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Activated sludge from the municipal wastewater treatment plant Breisgauer Bucht was used as
inoculum with a concentration corresponding to 30 mg dry solids per litre. The treatment plant
clarifies predominantly domestic wastewater and has a capacity of 600.000 inhabitant
equivalents. Sampling date of activated sludge was 21 July 2021. The dry solids (d.s.) content of
the activated sludge was 3.52 g/L. It was determined by weight measurements after drying at
105°C for 7.5 h. (mean of triplicate measurements). The activated sludge was washed twice with
tap water by settling the sludge, decanting the supernatant and re-suspending the sludge.

Duration of test (contact time):

60 d

Initial conc.:

100.9 other: ThOD/L

Based on:

ThOD

Remarks:

6.34 μL of the test item and 164 mL mineral medium with a pH of 7.6 were added into the test vessels. This corresponds to a concentration of 100.9 mg THOD/L.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium:
A: Potassium dihydrogenphosphate KH2PO4 8.50 g
Dipotassium hydrogenphosphate K2HPO4 21.75 g
Disodium hydrogenphosphate dihydrate Na2HPO4 * 2 H2O 33.40 g
Ammonium chloride NH4Cl 0.50 g
are dissolved in demineralised water and made up to 1 litre. The pH of the solution should be 7.4.

B: Calcium chloride dihydrate CaCl2 * 2 H2O 36.4 g
is dissolved in demineralised water and made up to 1 litre.

C: Magnesium sulfate heptahydrate MgSO4 * 7 H2O 22.5 g
is dissolved in demineralised water and made up to 1 litre.

D: Iron (III) chloride hexahydrate FeCl3 * 6 H2O 0.25 g
is dissolved in demineralised water, made up to 1 litre and stabilised with one drop of
concentrated HCl.
For preparation of the mineral medium 10 mL of solution (A) is mixed with 900 mL demineralised
water, 1 mL each of solutions (B), (C) and (D) are added and the volume is made up to 1 litre.
Before use, the mineral medium is aerated for at least half an hour and the pH is, if necessary,
adjusted to 7.4 ± 0.2.
The mineral medium used for this test was prepared by diluting 25 mL of solution (A) and 2.5 mL
each of solutions (B), (C) and (D) with demineralised water to a total volume of 2.5 L. The medium
was aerated for 4.5 h. The pH was 7.6 and was therefore not adjusted.


- Additional substrate: no
- Solubilising agent (type and concentration if used): no
- Test temperature: 21.2 – 21.4°C
- pH: 6 - 8.5
- pH adjusted: yes (mineral medium with a pH of 7.6)
- Aeration of dilution water: no
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: The systems OxiTop® (WTW / Xylem) and Sensomat (AQUALYTIC®) were used as test systems.
- Number of culture flasks/concentration: 3
- Method used to create aerobic conditions: no
- Method used to create anaerobic conditions: no
- Measuring equipment: The systems OxiTop® (WTW / Xylem) and Sensomat (AQUALYTIC®) were used as test systems. They consist of 500 mL narrow-necked glass bottles with rubber quiver inserts for NaOH pellets, which absorb the carbon dioxide produced. The liquid volume was fixed as 164 mL each. Magnetic stir bars were introduced into the bottles which were positioned on magnetic stirrers. The bottles were sealed tightly with the measuring heads with a measuring range of 500 – 1350 hPa.
- Test performed in closed vessels due to significant volatility of test substance: yes
- Details of trap for CO2 and volatile organics if used: NaOH pellets


SAMPLING
- Sampling frequency: 240 min
- Sampling method: Every 240 minutes the current pressure was measured and stored by each measuring head. At the end of the experiment pressure data were read out via an infrared interface to the controller unit.
- Sterility check if applicable: no
- Sample storage before analysis: no

CONTROL AND BLANK SYSTEM
- Inoculum blank: 3

- Toxicity control: One. 6.34 μL of the test item and 164 mL of the stock solution with 128.2 mg/L sodium acetate were added into the toxicity control vessel. This corresponds to a concentration of 200.9 mg ThOD/L. The pH was 7.5 and was not adjusted.


VALIDITY CRITERIA:
• The oxygen uptake of the inoculum blank in 28 days was within the range of 20 - 30 mg O2/L.
• The pH in the blank, test and abiotic control vessels was within the range of 6 – 8.5. In the
reference and toxicity control vessels, the pH was above >8.5, but the oxygen consumption in
these vessels was greater than 60% of ThOD.
• The difference of extremes of replicate values at the end of the test was less than 20%.
• The biodegradation of the reference item reached the pass level of 60% ThOD within 5 days.
• The degradation extent in the toxicity control was above 25% in 14 days based on ThOD
The test is valid according to OECD Test Guideline 301 F (July 1992).

Reference substance:

acetic acid, sodium salt

Remarks:

A stock solution of 128.2 mg/L sodium acetate in mineral medium was prepared. 164 mL of this stock solution were added into the reference vessels corresponding to a concentration of 100.0 mg ThOD/L. The pH was 7.5 and was not adjusted.

Key result

Parameter:

% degradation (O2 consumption)

Value:

73.9

Sampling time:

60 d

Key result

Parameter:

% degradation (O2 consumption)

Value:

43

Sampling time:

28 d

Details on results:

The degradation extent of the test item at the end of the test was 73.9% of ThOD without reaching
the plateau phase (60 d, mean of three replicates). On day 28, the mean degradation value was 43.0%. The test item did not reach the criteria for ready biodegradability (60% of ThOD within 28 days and within a 10-d window).
The test item reached the criterion to be considered as inherently biodegradable and non-persistent (60% of ThOD within 60 days).
The pH in the test vessels at the end of the test was 7.6.

Results with reference substance:

The reference compound sodium acetate reached the pass level of 60% ThOD within 5 days. The pH in the reference vessels at the end of the test was 9.5 – 9.6.

Validity criteria fulfilled:

yes

Remarks:

The test is valid according to OECD Test Guideline 301 F (July 1992) - see validity criteria in details on study design.

Interpretation of results:

inherently biodegradable, fulfilling specific criteria

Remarks:

The test item reached the criterion to be considered as inherently biodegradable and non-persistent (60% of ThOD within 60 days).

Conclusions:

Isobornyl acrylate achieved 43.0% (28d) and 73.9% (60d) biodegradation in a valid OECD 301F study. The 10-d window was failed. Therefore, the substance is considered as not readily biodegradable according to OECD guideline 301F, but inherently biodegradable and non-persistent.

Executive summary:

The biodegradability of Isobornyl acrylate exposed to microorganisms derived from activated sludge of a municipal sewage treatment plant was investigated under aerobic static exposure conditions.

The biodegradability of Isobornyl acrylate based on O₂consumption was calculated to be 43.0% after 28 days and 73.9% after 60 days as compared to the theoretical oxygen demand (ThOD).

 

The reference compound sodium acetate reached the pass level of 60% ThOD within 5 days, thus confirming suitability of inoculum and test conditions.

 

Isobornyl acrylate did not reach the pass level of 60% for ready biodegradability in the Manometric Respirometry Test within the 10-d window as well as after 28 days and, therefore, cannot be termed as readily biodegradable in the sense of the OECD guideline 301F.

In the enhanced screening test (60 d) for ready biodegradability in the Manometric Respirometry Test IBoA reached the pass level of 60% for inherent biodegradability and can be concluded as non-persistend.

 

 

 

 

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-05-09 - 2012-06-10

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test)

Version / remarks:

(2006), EN ISO 14593 (1999)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- lnoculum of the aqueous phase of non adapted activated sludge

- Source: Municipal sewage treatment plant, D-31137 Hildesheim

Reasons for the selection of the test system: Activated sludge from the sewage plant at Hildesheim is well suited as it receives predominantly municipal sewage and hardly any industrial chemical waste
.
- Pretreatment: The activated sludge was washed twice with autoclaved tap water. After the second washing the settled sludge was resuspended in mineral salts medium and was maintained in an aerobic condition
by aeration for 2.5 hours. Thereafter the sludge was homogenized with a blender. The supernatant was decanted and was maintained in an aerobic condition by aeration with COrfree air for 2 days.
10 ml/L were used to initiate inoculation.

- Colony forming units in the test solution: 10 E5 - 10 E8 CFU/L

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

test mat.

Initial conc.:

14.9 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

- Replicates: Triplicates (testend 5 replicates)
- TOC: 0.75 mg C/mg test item
- Test concentration: 20 mg/L (corresponding to 1.6 mg test item / test vessel)
- Carbon content in the vessel: 14.9 mg C/L
- Toxicity control: Test item in test concentration + 30 mg/L reference item
- Replicates: Triplicates (testend 5 replicates)
- Inoculum control: Mineral salts medium + inoculum
- Replicates: Triplicates (testend 5 replicates)
- Duration: 28 days
- Application: Once at test start
- Headspace to liquid ratio: 1 :2
- Test vessels / volume: Headspace flasks / 120 ml
- Test medium / volume: Mineral salts medium acc. to OECD 310 / 80 ml
- Agitation: Shaker (150 - 200 rpm)
- Temperature: 20 - 25 °C, (constant at ± 1 °C )
- Photoperiod: Low light conditions

Reference substance:

benzoic acid, sodium salt

Remarks:

as functional control

Test performance:

The adaptation phase of the functional control changed after 1 day into the degradation phase (degradation z 10 %). The course of the degradation phase was rapid and the pass level of 60 %
was reached after 2 days. The biodegradation came to 92 % after 28 days. The validity criterion degradation > 60 % after 14 d is fulfilled. The 95 % confidence interval on day 28 was 89 - 95 %

The biodegradation of the toxicity control reached 42 % within 14 days and it came to 54 % after 28 days. The biodegradation of the reference item was not inhibited by the test item in the toxicity control. The 95 % confidence interval on day 28 was 53 - 55 %.
The biodegradation of the test item is shown graphically in Figure 1 in comparison to the readily biodegradable functional control and the toxicity control. The test item replicate reached the 10 % level after 11 days and the biodegradation reached a mean value of 57 % at day 28. The 95 % confidence interval on day 28 was 50 - 64 %, the 60 % pass level was reached by 3 replicates

Parameter:

% degradation (CO2 evolution)

Value:

2

Sampling time:

9 d

Parameter:

% degradation (CO2 evolution)

Value:

26

Sampling time:

14 d

Parameter:

% degradation (CO2 evolution)

Value:

47

Sampling time:

21 d

Key result

Parameter:

% degradation (CO2 evolution)

Value:

57

Sampling time:

28 d

Remarks on result:

other: The 95% confidence interval on day 28 was 50 - 64 %.

Remarks:

3 of 5 replicates reached the pass level 60 % biodegradation within 28 days.

Details on results:

The total amount of C02 produced in 28 days was analysed by TIC measurements at 8 sampling times.
The adaptation phase of the functional control changed after 1 day into the degradation phase (degradation z 10 %). The course of the degradation phase was rapid and the pass level of 60 %
was reached after 2 days. The biodegradation came to 92 % after 28 days. The validity criterion degradation > 60 % after 14 d is fulfilled. The 95 % confidence interval on day 28 was 89 - 95 %
The biodegradation of the toxicity control reached 42 % within 14 days and it came to 54 % after 28 days. The biodegradation of the reference item was not inhibited by the test item in the
toxicity control. The 95 % confidence interval on day 28 was 53 - 55 % .
The biodegradation of the test item is shown graphically in Figure 1 in comparison to the readily biodegradable functional control and the toxicity control. The test item replicate reached the 10 % level after 11 days and the biodegradation reached a mean value of 57 % at day 28. The
95 % confidence interval on day 28 was 50 - 64 %, the 60 % pass level was reached by 3 replicates.

Results with reference substance:

86 % after 7d
94 % after 21 d
92 % after 28 d
The functional control reached the pass level of 60% after 2 days and came to the maximum of 94 % on day 21. The biodegradation rate came to 92 % on day 28. The 95% confidence interval on day 28 was 89 -95 %.

In the toxicity control containing both test and reference substance a biodegradation rate of 42% occurred within 14 days and came to the maximum of 54 % after 28 days. The biodegradation of the reference substance was not inhibited by the test substance in the toxicity control. The 95% confidence interval on day 28 was 53 - 55%.

The criteria of validity of the test have been met:

- The percentage of degradation of the reference substance in the control series is greater than 60% in 14 days;

- The mean amount of TIC (total inorganic carbon) produced in the inoculum controls at the end of the test was 0.55 mg C/L (validity criterion: TIC < 3 mg C/L).

The Degradation of the reference substance has not been inhibited by the presence of the test substance.

Validity criteria fulfilled:

yes

Remarks:

according to the guideline

Interpretation of results:

other: not readily biodegradable, but classified as not persistent

Conclusions:

In a valid guideline study (OECD 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test)), 57 % biodegradation was obtained after 28 days. The 10-day criterion for ready biodegradability was not achieved. However, in three of five samples, biodegradation was above 60 % after 28 days. In a prolonged test up to 56 days ist is expected that two further replicates would reach the pass level of 60 % biodegradation. Under this circumstances identification of the degradation products is not required.
Therefore, isobornyl acrylate is classified as not readily biodegradable but as not persistent.

Executive summary:

Under the conditions of the test, the percentage of biodegradation of Isobornyl acrylate was 57 % after 28 days (95% confidence interval on day 28 was 50 – 64 %; end of trial). A level of 10 % biodegradation was reached after 11 days. There was no inhibitory effect against micro-organisms observed. The 60 % pass level was reached by 3 of 5 replicates after 28 days. The validity criteria according to guideline OECD 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test) are fulfilled. Taking into account that Isobornyl acrylate is a volatile substance and is attempted to vaporize into the headspace which in this test had a ratio of 1:2 (headspace to liquid) and considering that 3 of 5 replicates reached the 60 % pass level after 28 days Isobornyl acrylate is considered not be persistent. In a prolonged test up to 56 days ist is expected that two further replicates would reach the pass level of 60 % biodegradation. Under this circumstances identification of the degradation products is not required.

In conclusion, the substance is regarded as not readily biodegradable, but not persistent.

 

 

 

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Description of key information

In an valid GLP OECD TG 301F (enhanced 60 days, 2021), the biodegradability of Isobornyl acrylate exposed to microorganisms derived from activated sludge of a municipal sewage treatment plant was investigated under aerobic static exposure conditions. The biodegradability of Isobornyl acrylate based on O2consumption was calculated to be 43.0% after 28 days and 73.9% after 60 days as compared to the theoretical oxygen demand (ThOD). Isobornyl acrylate did not reach the pass level of 60% for ready biodegradability in the Manometric Respirometry Test within the 10-d window as well as after 28 days and, therefore, cannot be termed as readily biodegradable in the sense of the OECD guideline 301F. In the enhanced duration of the screening test (60 d) IBoA reached the pass level of 60% for inherent biodegradability and can be concluded as non-persistend.

 

In an OECD TG 310 study, isobornyl acrylate was not readily biodegradable as all 5 replicates failed the ten day window. 3 of 5 replicates reached 60 % biodegradation within 28 days. As Isobornyl acrylate is a volatile substance and the test was not prolonged up to 56 days it is expected that further biodegradation would occur in all replicates so that the 60 % level would be reached in all 5 replicates. The expected primarily degradation products Isoborneol and acrylc acid are readily biodegradable.  
Isobornyl acrylate is not readily biodegradable in an OECD 310 test (Evonik 2013) but is also not persistent.

Primarily degradation products acrylic acid and isoborneol are readily biodegradable. Isobornyl acrylate is not readily biodegradable but is also not persistent.

 

In an OECD TG 301 F (28 days, 2008) the biodegradability of Isobornyl acrylate exposed to microorganisms derived from activated sludge of a municipal sewage treatment plant was investigated under aerobic static exposure conditions. The biodegradability of Isobornyl acrylate based on O2consumption was calculated to be 51% after 28 days as compared to the theoretical oxygen demand (ThOD). The biodegradation of Isobornyl acrylate reached 38% at the end of the 10-d window. Biodegradation of the test substance was observed after a lag phase of about 9 days. The procedure control sodium benzoate reached 82% biodegradation after 14 days, thus confirming suitability of inoculum and test conditions.

The calculated biodegradation based on DOC measurement reached 95% for Isobornyl acrylate and 99% for sodium benzoate. The data show that the consumed O2was used for partial mineralization of the test compound, since the determined degradation values based on BOD were lower as compared to those based on DOC.

Isobornyl acrylate did not reach the pass level of 60% for ready biodegradability in the Manometric Respirometry Test within the 10-d window as well as after 28 days and, therefore, cannot be termed as readily biodegradable in the sense of the OECD guideline 301.

 

As the enhanced OECD 301 F (2021) study showed biodegradation of 73.9% (60 d), IBoA can be concluded as non-persistend and inherently biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Type of water:

freshwater