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Long-term toxicity to fish

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Endpoint:
fish, juvenile growth test
Type of information:
experimental study
Adequacy of study:
key study
Study period:
17 Jan 2007 - 14 Feb 2007
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
The initial fish weight and the loading rate are lower than the recommended conditions of the OECD 215: 0.86 g (instead of 1 – 5 g) and 0.4 g/L (instead of 1.2 – 2.0 g/L); During the test, the pH was within a range of ± 0.9 pH units instead of ± 0.5
Qualifier:
according to
Guideline:
OECD Guideline 215 (Fish, Juvenile Growth Test)
Qualifier:
according to
Guideline:
OECD Guideline 204 (Fish, Prolonged Toxicity Test: 14-day Study)
Deviations:
yes
Remarks:
During the test, the pH was within a range of ± 0.9 pH units instead of ± 0.5 pH units.
GLP compliance:
yes (incl. certificate)
Remarks:
Hess. Ministerium für Umwelt, ländlichen Raum und Verbraucherschutz, Wiesbaden, Germany
Analytical monitoring:
yes
Details on sampling:
- Concentrations: 0.019, 0.061, 0.20, 0.63 and 2.0 mg test substance/L.
- Sampling method: One sample from the freshly prepared stock solution and duplicate samples from the freshly prepared test media of all test concentrations and the control were taken at the start of the test (day 0) and at one date in the second, third and fourth week (day 9, 19 and 23). For the determination of the stability of the test item under test conditions and of the maintenance of the test item concentrations during the test period, samples were taken in duplicate at four dates ( day 2, 12 21 and 26) from all test concentrations and the control. All samples were taken from the
approximate centre of the aquaria without mixing of the test media.
- Sample storage conditions before analysis: All samples were stored in the freezer (< -10°C), protected from light before measurement.
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Controls: water control
Test organisms (species):
Oncorhynchus mykiss (previous name: Salmo gairdneri)
Details on test organisms:
TEST ORGANISM
- Common name: Rainbow trout
- Source: Forellenzuchtbetrieb Wagenhausen, Bad Saulgau, Germany
- Age at study initiation (mean and range, SD): Juvenile males and females
- Length at study initiation (mean and range, SD): 4.18 ± 0.12 cm
- Weight at study initiation (mean and range, SD): 0.78 ± 0.09 g

FEEDING DURING TEST
- Food type and amount: commercial feed for Rainbow trout (4% dry weight based on the mean initial fish wet weight in each test vessel)
- Frequency: two times per day
Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
28 d
Test temperature:
15 - 16 °C
pH:
7.1 – 8.0
Dissolved oxygen:
At least 8.4 mg/L or higher
Nominal and measured concentrations:
Nominal concentrations: control, 0.019, 0.061, 0.20, 0.63 and 2.0 mg test substance/L
Measured concentrations: < LOQ, 0.012, 0.044, 0.15, 0.50 and 1.9 mg test substance/L
Details on test conditions:
TEST SYSTEM
- Test vessel: 24 L glass aquaria
- Material, size, headspace, fill volume: glass, 24 L, headspace: 2 L, fill volume: 22 L
- Aeration: Yes, test media were slightly aerated during the test period.
- Renewal rate of test solution: three times per week
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: < 1 g fish/L test medium

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to guideline
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: The test chambers were positioned under regulated lighting to produce an overall photoperiod of 16 h light and 8 h dark.
- Light intensity: 320 – 850 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality and signs of intoxication (at least once a day), growth parameters (at start and end of the test)


RANGE-FINDING STUDY
yes
Reference substance (positive control):
no
Duration:
28 d
Dose descriptor:
NOEC
Effect conc.:
0.15 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
other: growth rate
Duration:
28 d
Dose descriptor:
LOEC
Effect conc.:
0.5 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
other: growth rate
Details on results:
- Mortality and symptoms of intoxication: At the highest test concentration of 1.9 mg test item/L all fish were dead after 6 days, before they died the fish showed several signs of intoxication. No mortality was observed during the test in the test concentration of 0.50 mg test item/L. However, the fish showed reduced feeding, strong ventilation, strongly extended gills and the fish swam mainly on the water surface from day 7 until the end of the test. Furthermore, in the control and in the test concentrations of 0.012, 0.044 and 0.15 mg test item/L one fish died during the test, however the surviving fish showed no signs of intoxication and therefore the death could not be caused by the test item. Additionally, in the test concentration of 0.15 mg test item/L, a second fish died due to attacks of another fish in this concentration.
- Growth parameters: The mean body weight increased 150% in the control. At 0.012, 0.044 and 0.15 mg test item/L the mean body weight increase ranged between 130% and 146%. At 0.50 mg test item/L the mean body weight increased 65%.
- Pseudo specific growth rate: The mean pseudo specific growth rate for the control was determined to be 1.40. According to the results of the Dunnett’s multiple t-test (one sided smaller, α = 0.05) the pseudo specific growth did not differ between the control and the test concentration of 0.012, 0.044 and 0.15 mg test item/L. In contrast, the pseudo specific growth rate decreased significantly in the test concentration of 0.50 mg test item/L compared to the control (0.77).
Reported statistics and error estimates:
The NOEC and the LOEC for the pseudo specific growth rate were evaluated by the Dunnett’s multiple t-Test after testing the data for normal distribution and homogeneity of variance using Kolmogorov-Smirnov-test and Bartlett’s test, respectively.

Table 1: Effects of Preventol CMK on Rainbow trout (Oncorhynchus mykiss)

Day1

Control

Mean measured Preventol CMK concentration [mg/L]

0.012

0.044

0.15

0.50

1.9

Mortality and symptoms of intoxication
(number of dead fish / number of fish with intoxication symptoms2and observed symptoms of intoxication)

0
(after 2 h)

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

0 / 10
(TS, SR, DC)

1

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

7 / 10
(TS)

2

0 / 0

0 / 0

0 / 0

0 / 0

0 / 0

7 / 10
(SR, TS)

5

0 / 0

0 / 0

0 / 0

1 / 1

0 / 0

9 / 10
(SR, AP, KR)

6

0 / 0

0 / 0

0 / 0

1 / 1

0 / 0

10 / 10

7

0 / 0

0 / 0

0 / 0

1 / 1

0 / 10
(OB, SV)

10 / 10

8

0 / 0

0 / 0

0 / 0

1 / 1

0 / 10
(OB, SV, AK)

10 / 10

9

0 / 0

0 / 0

0 / 0

1 / 1

0 / 10
(OB, SV, AK)

10 / 10

12

0 / 0

0 / 0

0 / 0

1 / 1

0 / 10
(OB, SV, AK)

10 / 10

13

0 / 0

0 / 0

0 / 0

1 / 1

0 / 10
(OB, SV, AK)

10 / 10

14

0 / 0

0 / 0

0 / 0

1 / 1

0 / 10
(OB, SV, AK)

10 / 10

15

0 / 0

0 / 0

1 / 1

1 / 1

0 / 10
(OB, SV, AK)

10 / 10

16

0 / 0

0 / 0

1 / 1

2 / 23

0 / 0

10 / 10

19

1 / 1

1 / 1

1 / 1

2 / 2

0 / 5
(OB, SV)

10 / 10

20

1 / 1

1 / 1

1 / 1

2 / 2

0 / 3
(OB)

10 / 10

21

1 / 1

1 / 1

1 / 1

2 / 2

0 / 4
(OB)

10 / 10

22

1 / 1

1 / 1

1 / 1

2 / 2

0 / 2
(OB)

10 / 10

23

1 / 1

1 / 1

1 / 1

2 / 2

0 / 0

10 / 10

26

1 / 1

1 / 1

1 / 1

2 / 2

0 / 8
(OB)

10 / 10

27

1 / 1

1 / 1

1 / 1

2 / 2

0 / 2
(OB)

10 / 10

28

1 / 1

1 / 1

1 / 1

2 / 2

0 / 0

10 / 10

Body total weight
[g]

At start of the test
(mean
±SD)

0.86±0.09

0.86±0.05

0.88±0.05

0.85±0.07

0.86±0.08

0.85±0.08

At end of the test (mean±SD)

2.15±0.46

1.98±0.28

2.01±0.67

2.09±0.39

1.41±0.24

-

Pseudo specific growth rate

Mean±SD

1.40±0.29

1.29±0.20

1.22±0.45

1.38±0.26

0.77±0.24

-

Total length of the whole batch of fish (cm, mean values±SD):4.18±0.12

Body total weight of the whole batch of fish (g, mean values±SD):0.78±0.09

1. observation on each working day

2. dead fish are added to the sum of fish with symptoms

3. one fish died due to attacks of one other fish

SD: Standard deviation

Intoxication symptoms: AK: strongly extended gills, AP: apathy, BA: distended abdomen, DC: dark colouration, FV: fins clearly shortened or frayed out at the border, GA: exopthalmus, KR: convulsions, OB: fish mainly at the water surface, SA: mucous secretion, SR: fish lying on side or back on the bottom, SV: strong ventilation, TS: tumbling during swimming

*: Statistically significant difference from pooled controls (ά = 0.05) when tested with DUNNETT’s test.

Table 2: Validity criteria

Criterion from the guideline

Outcome

Validity criterion fulfilled

The dissolved oxygen concentration should be >60% of the air saturation value throughout the test.

The oxygen concentration in the test media did not fall below

60% of air saturation value during the study.

Yes

The water temperature must not differ by more than ± 1 °C between test chambers at any one time during the test and should be maintained within a range of 2 °C within the temperature ranges specified for the test species (Annex 2).

The water temperature did not differ by more than ± 1 °C

between test chambers at any time during the test and was within

the temperature range of 2°C given in the study plan.

yes

The mortality in the control(s) must not exceed 10 per cent at the end of the test.

10 %

yes

The mean weight should increase by at least the half of their mean initial weight over 28 days.

Start: mean 0.86 g

End: mean 2.15 g

yes

Validity criteria fulfilled:
yes
Remarks:
For further details please refer to “Any other information on results incl. tables”.
Conclusions:
28 d NOEC: 0.15 mg test item/L (pseudo specific growth rate)
28 d LOEC: 0.50 mg test item/L (pseudo specific growth rate)
Executive summary:

The long-term toxicity of p-chloro-m-cresol has been tested in a juvenile growth test with the Rainbow trout (Oncorhynchus mykiss) according to “OECD Guideline for Testing of Chemicals, Section 2, No. 204: “Fish, Prolonged Toxicity Test: 14-day Study”, adopted April 04, 1984 and No. 215: “Fish, Juvenile Growth Test”, adopted January 21, 2000 (Schneider & Wydra, 2007). 10 juvenile Rainbow trouts each were exposed to nominal concentrations of 0.019, 0.061, 0.20, 0.63 and 2.0 mg test item/L (corresponding to mean measured concentrations of 0.012, 0.044, 0.15, 0.50 and 1.9 mg/L) and a control for 28 days. As the mean recovery rate in the freshly prepared test concentrations was 96% (average for all concentrations) and 51% in the aged test media (average for all concentrations), the results are reported related to analytical mean concentrations of the test item. The daily recorded effects were mortality and symptoms of intoxication. Furthermore, at the start and the end of the test, the growth parameters body weight and length of surviving fish were determined.

The resulting NOEC (28 d) based on growth rate was 0.15 mg test item/L. The LOEC (28 d) was determined to be 0.15 mg test item/L.

Endpoint:
adult fish: sub(lethal) effects
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
21 Aug 1991 - 04 Sep 1991
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Qualifier:
according to
Guideline:
other: UBA-Draft method: “Prolonged Toxicity Test with Zebrafish -Brachydanio rerio” (1984)
Deviations:
no
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 204 (Fish, Prolonged Toxicity Test: 14-day Study)
Deviations:
no
GLP compliance:
yes
Analytical monitoring:
yes
Details on sampling:
- Concentrations: control, 0.01, 0.032, 0.1, 0.32, 1.0 and 3.2 mg test item/L.
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution was prepared to give the desired series of test concentrations. To achieve this 16 mg of the test item were added to 1 litres of dilution water. The solution was treated for 4 hours on a magnetic stirrer. The stock solution is freshly prepared every working day. On Fridays the solution is additionally prepared for Saturdays and on Saturdays the solution is prepared for Sundays.
- Differential loading: no
- Controls: yes, water control
Test organisms (species):
Danio rerio (previous name: Brachydanio rerio)
Details on test organisms:
TEST ORGANISM
- Common name: Zebrafish
- Source: West-Aquarium, Bad Lauterberg, Germany
- Age at study initiation (mean and range, SD): approx. 4 month
- Length at study initiation (length definition, mean, range and SD): 2.5 - 3.5 cm
- Feeding during test : yes

ACCLIMATION
- Feeding frequency during acclimation: Tetra Min fish food, ground; at least once a day
- Health during acclimation (any mortality observed): < 2%

Test type:
flow-through
Water media type:
freshwater
Limit test:
no
Total exposure duration:
14 d
Hardness:
At test start, hardness of dilution water was 15.3 °dH (275.4 mg/L CaCO3); during the test a value of 15 °dH (270.0 mg/L CaCO3) was detected.
Test temperature:
20 - 24 °C
pH:
7.0 - 7.5
Dissolved oxygen:
8.5 - 9.3 mg/L
Nominal and measured concentrations:
nominal: control, 0.01, 0.032, 0.1, 0.32, 1.0 and 3.2 mg/L
measured:control, < 0.014, 0.017, 0.076, 0.306, 1.044, 3.35 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: fish tanks
- Material, size, headspace, fill volume: glass, 300x135x200 mm, headspace: not given, fill volume: 5 L
- Aeration: yes
- Renewal rate of test solution (frequency/flow rate): Renewal of test solution about six times per day.
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Synthetic freshwater (according to ISO 7346)
- Alkalinity: At test start, the concentration of the major ions Ca and Mg was 89 mg/L and 15 mg/L, respectively. The acidity (to pH 4.3) was 0.80 mmol/L. During the test, concentrations of Ca and Mg were 91 mg/L and 14 mg/L, respectively. The acidity (to pH 4.3) was 0.77 mmol/L.

OTHER TEST CONDITIONS
- Photoperiod: 16 h light : 8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Mortality, incidence of sub-lethal effects as well as behavioural responses were recorded every 24 hours; Fish size (body length): was measured at day 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; Wet body weight: measured at end of exposure (after 14 days)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: approx: 3.2

RANGE-FINDING STUDY
- Test concentrations:
1: 1, 10 and 100 mg/L
2: 0.32 mg/L and 3.2 mg/L
- Results used to determine the conditions for the definitive study:
1: LC100 (72 h) of 10 mg/L
2: 3 fish died at 3.2 mg/L
Reference substance (positive control):
no
Duration:
14 d
Dose descriptor:
NOEC
Effect conc.:
1 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Duration:
14 d
Dose descriptor:
LOEC
Effect conc.:
3.2 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality

Table 1: Cumulative mortality and behavioural observations (Results for Control: Mortality = 0; no visible effects)

Day

Nominal Concentration [g/L]

0.01

0.032

0.10

0.32

1.0

3.2

Dead

Obs.

Dead

Obs.

Dead

Obs.

Dead

Obs.

Dead

Obs.

Dead

Obs.

0

0

N

0

N

0

N

0

N

0

N

0

A, B, D, F

1

0

N

0

N

0

N

0

N

0

N

8

A, B, D, F

2

0

N

0

N

0

N

0

N

0

N

8

A, C, D, G

3

0

N

0

N

0

N

0

N

0

N

9

A, C, D, G

4

0

N

0

N

0

N

0

N

0

N

9

E

5

0

N

0

N

0

N

0

N

0

N

10

--

6

0

N

0

N

0

N

0

N

0

N

--

--

7

0

N

0

N

0

N

0

N

0

N

--

--

8

0

N

0

N

0

N

0

N

0

N

--

--

9

0

N

0

N

0

N

0

N

0

N

--

--

10

0

N

0

N

0

N

0

N

0

N

--

--

11

0

N

0

N

0

N

0

N

0

N

--

--

12

0

N

0

N

0

N

0

N

0

N

--

--

13

0

N

0

N

0

N

0

N

0

N

--

--

14

0

N

0

N

0

N

0

N

0

N

--

--

Abbreviations of behavioural observations

N       Normal

A       Uncontrolled swimming action

B       Gasping for air; irregular breathing

C       Abnormal swimming action

D       Uncontrolled collision with aquarium walls

E       Motionless, uncontrolled swimming action when touched

F       No fed intake

G       Reduced fed intake

Table 2: Total wet weight and body length of test fish at the end of the study

Day

Body length [cm] at various test concentrations [mg/L]

Control

0.01

0.032

0.10

0.32

1.0

3.2

1

3.3

3.3

3.0

3.3

3.3

3.1

2.8

2

3.0

3.0

2.8

3.2

3.0

3.0

3.0

3

3.1

3.5

3.2

3.4

3.2

3.0

3.0

4

2.7

3.5

3.1

3.5

3.1

3.2

3.1

5

3.5

3.2

3.4

3.2

3.0

3.0

3.0

6

3.2

3.2

3.4

3.1

3.1

3.1

2.9

7

3.0

3.2

3.0

3.0

3.2

3.1

3.1

8

3.0

3.3

2.9

3.5

3.3

3.3

3.0

9

3.1

3.3

3.4

2.9

3.0

3.5

3.0

10

3.1

2.9

3.1

3.2

2.7

2.8

2.7

 

Body weight of 10 fish [g]

14

2.81

2.58

2.78

2.84

3.07

3.10

2.94

Validity criteria fulfilled:
yes
Remarks:
For further details please refer to “Any other information on results incl. tables”.
Conclusions:
NOEC (14 d) = 1 mg/L
Executive summary:

The prolonged toxicity of p-chloro-m-cresol to Zebrafish (Brachydanio rerio) was tested by Caspers & Müller (1991). The test was carried out based on the method described by UBA-Draft method: ”Prolonged Toxicity Test with Zebrafish – Brachydanio rerio (1984)”. This method is comparable to OECD Guideline 204 “Fish, Prolonged Toxicity Test: 14-day study” (adopted 1984). This report is a re-evaluation study report 212 A/90 FL "Fish, Prologned Toxicity Test of

Prevento! CMK", based on the corresponding raw data from the GLP archives (BIS-SUAAnalytics) and additional information from the executing laboratory. Recent regulatory requirements necessitate this re-evaluation.

Chemical exposures were conducted for 14 days, mortality and abnormal behaviour was recorded daily.

Results based on nominal concentrations, due to mean measured concentrations from 104 to 105 % at the NOEC and LOEC concentration, respectively.

Based on the observed abnormal behaviour and mortality in the highest concentration and no observed effects in the treatment below, the LOEC (14 d) was determined to be 3.2 mg a.i./L and the NOEC (14 d) as 1.0 mg/L.

Endpoint:
fish, juvenile growth test
Remarks:
adult fish: sub(lethal) effects
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
Refer to analogue justification document provided in IUCLID section 13.
Duration:
28 d
Dose descriptor:
NOEC
Effect conc.:
0.15 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other:
Remarks:
source, CAS 59-50-7, key rel 2, Schneider & Wydra 2007
Duration:
28 d
Dose descriptor:
NOEC
Effect conc.:
0.5 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other:
Remarks:
source, CAS 59-50-7, key rel 2, Schneider & Wydra 2007
Duration:
14 d
Dose descriptor:
NOEC
Effect conc.:
1 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks on result:
other:
Remarks:
source, CAS 59-50-7, rel 1, Caspers & Müller 1991
Duration:
14 d
Dose descriptor:
LOEC
Effect conc.:
3.2 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks on result:
other:
Remarks:
source, CAS 59-50-7, rel 1, Caspers & Müller 1991

Description of key information

NOEC (28 d): 0.15 mg/L (measured, Oncorhynchus mykiss), read-across

Key value for chemical safety assessment

EC10, LC10 or NOEC for freshwater fish:
0.15 mg/L

Additional information

No study investigating the toxicity of sodium p-chloro-m-cresolate (CAS 15733-22-9)to long-term fish is available. Therefore, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 a read-across to the source substance (p-chloro-m-cresol, CAS 59 -50 -7) which isthe main transformation product of the target substancesodium p-chloro-m-cresolate (CAS 15733-22-9) is applied.

The source substance p-chloro-m-cresol is the common compound in this analogue approach and is solely responsible for the (absence of) effects.Thus, the source substance is considered a suitable representative for the evaluation of the toxicity of the target substance to aquatic organisms. The read-across approach is justified in detail within the analogue justification in IUCLID section 13.

One key (Schneider & Wydra 2007) and one supporting study (Caspers & Müller 1991) are available investigating the long-term toxicity of the source substance p-chloro-m-cresol (CAS 59-50-7) to freshwater fish. The key study was conducted according to “OECD Guideline for Testing of Chemicals, Section 2, No. 204: “Fish, Prolonged Toxicity Test: 14-day Study”, adopted April 04, 1984 and No. 215: “Fish, Juvenile Growth Test”, adopted January 21, 2000. Ten juvenile Rainbow trouts each were exposed to nominal concentrations of 0.019, 0.061, 0.20, 0.63 and 2.0 mg/L (corresponding to mean measured concentrations of 0.012, 0.044, 0.15, 0.50 and 1.9 mg/L) and a control for 28 days. As the mean recovery rate in the freshly prepared test concentrations was 96% (average for all concentrations) and 51% in the aged test media (average for all concentrations), the results are reported related to analytical mean concentrations of the test item. The daily recorded effects were mortality and symptoms of intoxication. Furthermore, at the start and the end of the test, the growth parameters body weight and length of surviving fish were determined. The resulting NOEC based on growth rate was 0.15 mg test item/L. The LOEC was determined to be 0.15 mg test item/L.

Additionally, the prolonged toxicity of the source substance p-chloro-m-cresol to zebrafish (Brachydanio rerio) was tested in the supporting study. The test was carried out based on the method described by UBA-Draft method: ”Prolonged Toxicity Test with Zebrafish – Brachydanio rerio (1984)”. This method is comparable to OECD Guideline 204 “Fish, Prolonged Toxicity Test: 14-day study” (adopted 1984). Chemical exposures were conducted for 14 days, mortality and abnormal behaviour was recorded daily. Fish were exposed to nominal concentrations of 0.01, 0.032, 0.1, 0.32, 1.0 and 3.2 mg/L (corresponding to mean measured concentrations of < 0.014, 0.017, 0.076, 0.306, 1.044, 3.35 mg/L) Results were based on nominal concentrations, due to mean measured concentrations from 104 to 105 % at the NOEC and LOEC concentration, respectively. Based on the observed abnormal behaviour and mortality in the highest concentration and no observed effects in the treatment below, the LOEC was determined to be 3.2 mg/L and the NOEC as 1.0 mg/L.

Based on the available results from a structurally similar source substance (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) which is the main transformation product of the target substance and is characterized by a similar ecotoxicological profile and comparable structure, it can be concluded thatsodium p-chloro-m-cresolatehas effects in the same range as the target substance.