6H-Furo[2',3':4,5]oxazolo[3,2-a]pyrimidin-6-one, 2,3,3a,9a-tetrahydro-3-hydroxy-2-(hydroxymethyl)-7-methyl-, (2S,3S,3aR,9aS)-

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Oct 2010 - Marc 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Fish bioconcentration test in carp with Anhydrothymidine

Qualifier:

according to guideline

Guideline:

other: OECD guideline No. 305, 1996

Qualifier:

according to guideline

Guideline:

other: Commission Regulation (EC) No 440/2008, Part C.13, 2008

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

During the bioconcentration test, samples were taken from the test medium and from the fish for
several purposes and at several timepoints:
Analysis of medium: 24 samples
Analysis of fish: 60 fish
Fish lipid extraction: 16 fish

Uptake phase Frequency No. of water samples No. of fish per conc.
(days) control low high control low high
Check -1 1 1 1 - - -
Start 0 1 1 1 - - -
1st 1 1 1 1 2 4 4
2nd 3 1 1 1 2 4 4
3rd 7 1 1 1 2 4 4
4th 14 1 1 1 2 4 4
5th 21 1 1 1 2 4 4
6th

Vehicle:

yes

Remarks:

adjusted ISO-medium

Details on test solutions:

Adjusted ISO medium, formulated using RO-water (tapwater purified by reverse osmosis; GEON Waterbehandeling, Berkel-Enschot, The Netherlands) with the following composition:
CaCl2.2H2O 211.5 mg/l
MgSO4.7H2O 88.8 mg/l
NaHCO3 46.7 mg/l
KCl 4.2 mg/l

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Source Zodiac, proefacc, “De Haar Vissen”, Wageningen University and Research Centre, The Netherlands
Initial fish length 5.4 ± 0.3 cm, based on measurement of all fish used for this test
Initial fish weight 4.53 ± 0.62 g, based on weighing of all fish used for this test
Characteristics F1 from a single parent-pair bred in UV-treated water.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

28 d

Hardness:

179 mg calcium carbonate per litre

Test temperature:

20-25°C

pH:

7.1 to 8.0

Dissolved oxygen:

7.0 to 9.3 mg/l

Nominal and measured concentrations:

Time of measurement measured Anhydrothymidine concentration (mg/l)
(days) Target concentration Target concentration
0.10 mg/l 1.0 mg/l
Actual Actual
0 0.102 0.96
1 0.102 0.95
3 0.103 0.95
7 0.095 1.03
14 0.110 1.06
21 0.104 1.15
28 0.095 0.93

Details on test conditions:

Analyses showed that the actual concentrations were in agreement with the target concentrations (93-
115%). The mean concentrations of Anhydrothymidine were 0.10 ± 0.0052 mg/l and 1.0 ± 0.081 mg/l
at target concentrations of 0.10 and 1.0 mg/l, respectively. The measured concentrations varied within
the ± 20% window of the mean concentration at both target concentrations.

Reference substance (positive control):

no

Key result

Duration:

28 d

Dose descriptor:

other: BCF

Effect conc.:

0.066 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: bioconcentration

Key result

Duration:

28 d

Dose descriptor:

other: BCF

Effect conc.:

0.053 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: bioconcentration

Validity criteria fulfilled:

yes

Conclusions:

The bioconcentration study investigated the possible bioconcentration of Anhydrothymidine in carp exposed to two different concentrations for a period of 28 days in a flow through system.
The mean BCF-values of Anhydrothymidine at target concentrations of 0.10 and 1.0 mg/l were 0.066 ± 0.036 and 0.053 ± 0.026, respectively. Therefore, the uptake of Anhydrothymidine by fish proved to be insignificant.
Hence there is no substantial risk for bioconcentration of Anhydrothymidine in fish.

Description of key information

The bioconcentration study investigated the possible bioconcentration of Anhydrothymidine in carp exposed to two different concentrations for a period of 28 days in a flow through system.

The mean BCF-values of Anhydrothymidine at target concentrations of 0.10 and 1.0 mg/l were 0.066 ± 0.036 and 0.053 ± 0.026, respectively. Therefore, the uptake of Anhydrothymidine by fish proved to be insignificant.

Hence there is no substantial risk for bioconcentration of Anhydrothymidine in fish.