4-(4-isopropoxyphenylsulfonyl)phenol

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

fish, juvenile growth test

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 1998-07-18 to 199-04-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 215 (Fish, Juvenile Growth Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Water samples were filtered over a 0.45 µm HV-filter. For determination of concentration levels higher than 0.1 mg/L 100 µL of the filtered sample were injected into the LC system.

Vehicle:

no

Details on test solutions:

D-8 was tested under flow through conditions within the limits of solubility in water. Test concentrations were dosed from concentrated solutions in tertiary butyl alcohol (TBA).

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: Cyprinus carpio (L.)
- Strain: male carp population (XY) progeny of homozygous "super male" (YY) and normal female (XX)
- Source: Fish Culture and Fisheries Group; Department of Animal Sciences, Wageningen Agricultural University (The Netherlands)
- Age at study initiation: 55 days post hatch
- Weight at study initiation: 1.09 (0.6 - 1.7) ± 0.26 g

FEEDING DURING TEST
- Food type: Provimi
- Amount: 5 % of wet body weight
- Frequency: Daily in three feds

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

28 d

Test temperature:

24.2 - 25.4 °C

pH:

7.1 - 8.5

Dissolved oxygen:

6.8 - 8.8 mg/L

Nominal and measured concentrations:

Nominal: 0; 0.02; 0.2; 2.0 mg/L
Measured: 0.017; 0.20; 1.98 mg/L

Details on test conditions:

- The dilution water used was ground water (Linschoten water) from a locality near Linschoten (The Netherlands). Linschoten water is suitable for the culturing of Cayprinus carpio.
- The test aquaria were connected to an intermittent flow-through system. Every 15 min each test aquarium was supplied with ca. one litre newly prepared solution. The flow-through test was carried out in full glass aquaria of 25 L, each containing 20 L of exposure media, covered with a glass plate. The aquaria were cleaned once a week when the fish were weighed.
- Rational for concentration selection: The highest concentration used for the test is based on 1/10 of the LC50 (96h) value of 18.8 mg/L in fish.

Reference substance (positive control):

yes

Remarks:

17β-estradiol at 0.001 mg/L

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

> 2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

gonadal histology

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

> 2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Exposure to D-8 did not induce any estrogenic effect, as evidenced by an oviduct. Most of the fish exposed to D-8 and to the dilution water were at an undifferentiated stage (96 %), while 4 % already had developed normally as males as evidenced by the presence of a vas deferens. Both gonads of all fish examined in this exposure showed a single point of attachment. This is the normal stage of development of 80-d old male fish.
- No statistically significant effects on growth of the test fish were observed at any concentration of D-8 after 28 days of exposure. The test fish grew rapidly from an intial weight of ca. 1 g to population average of 2.50 - 2.76 g.
- No mortality or abnormal behaviour was observed in any of the test concentrations during the exposure period.

Results with reference substance (positive control):

Positive control substance: 17β-estradiol
After 28 days exposure (83 dph = days post hatch), all the male carp (100 %) exposed to the natural estrogen (positive control) developed a female reproductive tract (oviduct). The formation of an oviduct is known to be estrogen dependent and is characterised by the two points of attachment of the gonad to the coelomic wall.
The weights of the fish exposed to the positive control were similar to the test item exposure group.

Reported statistics and error estimates:

Statistical significance for growth was determined by the two-tailed Dunnett-test with a 95 % and 99 % significance level. In both cases the observations at each concentration were compared with those of the control. In case of significance at the 99 % level only that significance is given.
Statistical significance for the formation of an oviduct was determined with the chi square test with a 95 % and 99 % significance level. In both cases the observations at each concentration were compared with those of the control. In case of significance at the 99 % level only that significance is given.

Table 1. Analytical results for D-8

Nominal concentration [mg/L]	Average measured concentration [mg/L] (SD)	% of nominal
0	<0.001	-
0.02	0.017 (0.0004)*	85
0.2	0.20 (0.017)*	100
2.0	1.98 (0.08)*	99

* Standard deviation for n = 5

Table 2. Summary results on the effects of the test substance D-8 on the development of the reproductive tract of Cyprinus carpio.

Treatment (actual concentration in mg/L)	Type of reproductive tract, after 28 days exposure
	(u)	(o)	(d)
D-8 0, N = 12	96 % (23/24)	-	4 % (1/24)
TBA control, N = 12	100 % (24/24)	-	-
17β-estradiol 0.001*, N = 12	-	100 % (24/24)	-
D-8 0.017, N = 12	96 % (23/24)		4 % (1/24)
D-8 0.20, N = 12	96 % (23/24)		4 % (1/24)
D-8 1.98, N = 12	96 % (23/24)		4 % (1/24)

* nominal concentration

u: undifferentiated, o: oviduct, d: vas deferens.

N: number of fish examined.

(n): number of gonads observed.

Validity criteria fulfilled:

yes

Conclusions:

Exposure to D-8 did not induce any estrogenic effect, as evidenced by an oviduct formation, up to a concentration of 1.98 mg/L. The NOEC of D-8 was considered to be greater than 1.98 mg/L.

Executive summary:

The estrogenic effects of D-8 on all-male carp Cyprinus carpio, were determined using the draft OECD 215 Guideline for a "Fish, Juvenile Growth Test" and a TNO method in accordance with the OECD GLP principles. 12 fish per vessel were exposed to the following nominal concentrations of 0.02, 0.2 and 2 mg/L. The measured concentrations were determined to be in the ± 20 % range from the nominal concentrations. All male carp were exposed for 28 days to the test item. D-8 did not induce any estrogenic effect, as evidenced by no oviduct formation in any of the test concentrations. Most of the fish exposed to D-8 and dilution water were at an undifferentiated stage (96 %), while 4 % already had developed normally as males as evidenced by the presence of a vas deferens. Both gonads of all fish examined in this exposure showed a single point of attachment. This is the normal stage of development of 80-d old male fish. The NOEC for feminisation and growth was therefore considered to be greater than 2 mg/L.

Description of key information

Exposure to D-8 did not induce any estrogenic effect, as evidenced by an oviduct formation, up to a concentration of 2 mg/L. The NOEC of D-8 was considered to be greater than 2 mg/L.

Additional information

The estrogenic effects of D-8 on all-male carp Cyprinus carpio, were determined using the draft OECD 215 Guideline for a "Fish, Juvenile Growth Test" and a TNO method in accordance with the OECD GLP principles. 12 fish per vessel were exposed to the following nominal concentrations of 0.02, 0.2 and 2 mg/L. The measured concentrations were determined to be in the ± 20 % range from the nominal concentrations. All male carp were exposed for 28 days to the test item. D-8 did not induce any estrogenic effect, as evidenced by no oviduct formation in any of the test concentrations. Most of the fish exposed to D-8 and dilution water were at an undifferentiated stage (96 %), while 4 % already had developed normally as males as evidenced by the presence of a vas deferens. Both gonads of all fish examined in this exposure showed a single point of attachment. This is the normal stage of development of 80-d old male fish. The NOEC for feminisation and growth was therefore considered to be greater than 2 mg/L.