3,5,5-trimethylcyclohex-2-enone

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Test procedure according to guideline without detailed documentation

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 305 (Bioconcentration: Flow-through Fish Test)

Deviations:

not specified

Principles of method if other than guideline:

Method: other: corresponding to OECD guideline 305 C

GLP compliance:

not specified

Details on sampling:

Frequency of analysis:
water: twice a week
fish: every two weeks

Vehicle:

yes

Details on preparation of test solutions, spiked fish food or sediment:

For the preparation of the stock solution suitable solvents and surfactants were used (EC50 -values of these compounds are presented)

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Fish were supplied from Sugishima fish farm
- Fish were kept in an acclimatisation tank for 1-2 months at a temperature of 25 +/- °C after external desinfection in an aqueous solution
containing 50 mg/L Terramycin and 7 g/L sodium chloride

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

42 d

Test temperature:

25 °C

Dissolved oxygen:

6-8 mg/l;

Details on test conditions:

ACCLIMATISATION:
- fish were kept in tank at a temperature of 25 +/- 2°C for ca. 28 days
- After this period, the fish were transferred into test tanks

TEST SYSTEM
1) Test tank: glass tank, water volume 100 L
2) Number of fish/level: 15-20
3) Duration of exposure: 6-8 weeks
4) Flow-through system (flow rate 200-800 ml/min, dilution water = groundwater from the test site)
5) Feeding during test: pelleted feed for carps

Nominal and measured concentrations:

0.5 mg/l

Type:

BCF

Value:

> 1.1 - <= 1.8 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: Conc.in environment / dose:0.5 mg/L

Type:

BCF

Value:

< 10 dimensionless

Basis:

whole body w.w.

Remarks on result:

other: Conc.in environment / dose:0.05 mg/L

Elimination:

not specified

Reference 2

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

Method: other: Flow-through Bioaccumulation Test

GLP compliance:

not specified

Radiolabelling:

yes

Details on sampling:

- samples of 5 ml water and 5 fish each on days 1, 2, 4, 7, 10, 14 (other  substances: also 21 and 28) of exposure; control water on days 0, 28;
- samples of 5 fish on days 1, 2, 4, and 7 of depuration;

Vehicle:

no

Details on preparation of test solutions, spiked fish food or sediment:

- 50 ul (out of 50 ml) of stock solution thoroughly mixed with 500 ml  water before introduction into aquarium

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- bluegill sunfish (Lepomis macrochirus)
- source: commercial fish farm in Connecticut
- wet weight 0.37 +/- 0.18 to 0.94 +/- 0.34 g;
- length 25 +/- 3 to 32 +/- 4 mm;
- acclimation period 30 days

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

14 d

Total depuration duration:

7 d

Hardness:

total hardness: 35 mg/l as CaCO3

Test temperature:

16 +/-1°C

pH:

7.1

Details on test conditions:

TEST EQUIPMENT
- well water, pH 7.1, 
- glass aquaria of 40 cm length, 20 cm width, 25 cm height / 19 cm depth;
- turnover rate six to seven aquarium volumes per day;
- temperature 16 +/- 1 °C; 
- no aeration; regular determination of dissolved oxygen;

TEST PROCEDURE
- 100 fish per aquarium
- dry pelleted food ad libitum on alternating days
- removal of feces as deemed necessary
- duration until equilibrium, maximum 28 days (isophorone: 14 days),  
followed by:
- transfer to aquarium with pollutant-free water;
- further duration 7 days

Nominal and measured concentrations:

92.4 µg/l +/- 10.5 µg/l

Type:

BCF

Value:

7 dimensionless

Basis:

whole body w.w.

Time of plateau:

14 d

Calculation basis:

steady state

Elimination:

yes

Parameter:

DT50

Depuration time (DT):

1 d

Half-life in tissues = 1 day

Validity criteria fulfilled:

yes

Conclusions:

The results indicate that isophorone has a very low potential for bioaccumulation.

Executive summary:

The bioaccumulation potential of Isophorone was evaluated in a bioaccumulation study with bluegill sunfish (Lepomis macrochirus) according to accepted scientific principles. The BCF after 14 days of exposure was calculated to be 7 indicating that Isophorone has a very low bioaccumulation potential. The halflife which was derived from a 7-day depuration phase was calculated to be <1 day.

The reliability of the study was assessed as "reliable with restrictions":

BCF: 7

DT50: >1 day

Description of key information

The bioconcentration factor was calculated from a flow -through fish test that was conducted with 14C labelled substance. The exposure concentration was 92.4 µg/l for 14 days with a subsequent depuration phase of 7 days (Veith, 1980).

Key value for chemical safety assessment

BCF (aquatic species):

7 dimensionless

Additional information

The bioaccumulation potential of the substance was evaluated in a bioaccumulation study with bluegill sunfish (Lepomis macrochirus) according to accepted scientific principles. The BCF after 14 days of exposure was calculated to be 7 indicating that the substance has a very low bioaccumulation potential. The half-life which was derived from a 7-day depuration phase was calculated to be <1 day (Veith 1980).  The low potential for bioaccumulation was also demonstrated in an OECD 305 study (with limited documentation) with Cyprinus carpio which reveals a BCF of <10 (CITI, 1992).