2,6-diisopropylnaphthalene

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

Cited as Directive 84/449/EEC, C.1 ("Acute toxicity for fish")

Deviations:

yes

Remarks:

: initial test concentration > water solubility, followed by a decrease of >20 % during the time interval down to the maximum water solubility

Principles of method if other than guideline:

Limit test with the maximum concentration technically achievable, performed according to Safepharm Standard Protocol Number FT/12/1/89.

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test substance was dissolved in 10% Tween 80 in acetone to form a preliminary solution.
- Controls: 1 blank and 1 vehicle control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): 10% Tween 80 in acetone
- Concentration of vehicle in test medium: 100 µL/L auxiliary solvent

Test organisms (species):

Leuciscus idus

Details on test organisms:

TEST ORGANISM
- Common name: golden orfe
- Source: Midland Waterlife, Derbyx, U.K.
- Age at study initiation (mean and range, SD): no data
- Length at study initiation (length definition, mean, range and SD): 5.6 cm (S.D = 0.2 cm)
- Weight at study initiation (mean and range, SD): 1.75 g (S.D. = 0.12 g)
- Feeding during test
- Food type: Tetramin flake food
- Amount: no data
- Frequency: daily

ACCLIMATION
- Acclimation period: 7 days
- Acclimation conditions (same as test or not): yes
- Type and amount of food: Tetramin flake food
- Feeding frequency: daily, discontinued 48 h prior to the test
- Health during acclimation (any mortality observed): 2% in 7 days prior to the test

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Post exposure observation period:

no

Hardness:

50 mg/L(as CaCO3)

Test temperature:

21 to 22°C

pH:

8.0 to 8.4

Dissolved oxygen:

8.3 to 8.7 mg/L

Nominal and measured concentrations:

nominal: 0.5 mg/L
measured: 0.55 mg/L (n=2) initial conc.; 0.135 mg/L (n=2) after 24 h (end of initial test period); 0.098 mg/L (n=2) after 96 h (end of 3rd renewal period), average 24h values = 0.12 mg/L (n =4), corresponding to ~23 % of nominal.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): glas aquaria holding 20 L of test media
- Aeration: via narrow bore glass tubes
- Renewal rate of test solution (frequency/flow rate): daily
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of animals per concentration: 20
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 1
- Biomass loading rate: 0.88 g/L

TEST MEDIUM / WATER PARAMETERS (mean parameters over three months)
- Source/preparation of dilution water: dechlorinated laboratory tap water
- Total organic carbon: 1.03 mg/L
- Alkalinity: 9.81 mg/L (CaCO3)
- Ca/mg ratio: 12/2.6
- Conductivity: 114 µS/cm

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light

TEST CONCENTRATIONS
- Spacing factor for test concentrations: only one test concentration used
- Justification for using less concentrations than requested by guideline: low solubility of test substance

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

ca. 0.24 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: mortality and behaviour

Remarks on result:

other: averaged geometric mean of initial and measured effect concentration at 24 and 96 h

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: no
- Observations on body length and weight: no data
- Other biological observations: no
- Mortality of control: no
- Other adverse effects control: no
- Abnormal responses: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no data

Validity criteria fulfilled:

yes

Conclusions:

No acute toxicity towards fish within the range of water solubility: Solubility of test substance in water is too low to result in concentrations toxic to fish in a short term tests.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Basic data given

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: Testing method for industrial waste water - Acute toxicity test by fish - JIS K 0102-1998, 71

Principles of method if other than guideline:

Japanese national standard JIS K 0102-1998, 71

GLP compliance:

yes

Analytical monitoring:

not specified

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test substance was mixed with a 10fold portion of Tween 80. This mixture was dissolved in deionized water to prepare a stock solution of 1000 mg/L.
- Controls: yes
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Tween 80

Test organisms (species):

Oryzias latipes

Details on test organisms:

TEST ORGANISM
- Common name: medaka, Japanese killifish
- Source: Nakajima Fish Farm, Kumamoto, Japan
- Length at study initiation: 3.2 cm on average
- Weight at study initiation: 0.31 g on average
- Feeding during test: no data

ACCLIMATION
- Acclimation period: at least 18 d
- Acclimation conditions (same as test or not): yes
- Type and amount of food: no data
- Health during acclimation (any mortality observed): no mortality

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

no

Hardness:

77.5 mg/L (Ca, Mg; analytical value of dilution water)

Test temperature:

23.9 - 24.4°C

pH:

7.5 - 7.9

Dissolved oxygen:

6.7 - 7.5 mg/L

Nominal and measured concentrations:

0.953, 1.71, 3.09, 5.56, and 10 mg/L (no information if nomimal or measured concentrations)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: glas gallon bottle
- Fill volume: 3.85 L
- Aeration: no data
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate): every 8 to 16 h
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): no data
- Biomass loading rate: 0.4 g/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ground water from the site of the laboratory (water quality according to OECD TG 305)
- Particulate matter: < 1 mg/L
- Metals:
- Pesticides: < 0.0001 mg/L
- Chlorine: < 0.01 mg/L
- Alkalinity: 158 mg/L
- Ca/mg ratio:
- Conductance: 493 µS/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: once every 6 month

OTHER TEST CONDITIONS
- Adjustment of pH: no

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8

Reference substance (positive control):

yes

Remarks:

test substance: sodium pentachlorophenol

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

0.95 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2.44 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

5.56 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortality of control: no mortality

Results with reference substance (positive control):

48 h LC50 of sodium pentacholorphenol for test fish of the same lot was 0.621 mg/L

Reported statistics and error estimates:

96h LC50 was calculated by the method of Doudoroff.

Validity criteria fulfilled:

no

Remarks:

no information on measured test substance concentration throughout the test

Conclusions:

No acute fish toxicity in the range of water solubility.

Reference 3

Endpoint:

short-term toxicity to fish

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 provided in IUCLID section 13

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

0.95 ng/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2.44 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

5.56 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Description of key information

 LC50 (96 h): 2.44 mg/L (nominal); read-across

Additional information

No short-term fish toxicity study concerning only 2,6-diisopropylnaphthalene (2,6-DIPN) was available. Therefore two acute fish studies using Bis(isopropyl)naphthalene (DIPN)was used in a read-across approach for assessment of the acute toxicity towards fishes of 2,6-DIPN.

Bis(isopropyl)naphthalene (DIPN) is an isomeric mixture, which consists of seven isomers (1,3-, 1,4-, 1,5-, 1,6-, 2,6- and 2,7-DIPN).

Two appropriate studies performed with DIPN on short-term toxicity to fish have been identified. Both of them have shortcomings. Only one reported a LC50 which can be considered to be reliable (Kikushima et al. 2003). But for this study also, validity criteria are not fulfilled (use of vehicle, no information on analytical test concentration measurements).

For only one study the concentration used is in the range of the maximum water solubility of DIPN (Handley/Safepharm, 2003). This study has been selected as key study. It is a limit test with a concentration (0.5 mg/L) slightly above the water solubility of DIPN. Test substance concentrations were measured and demonstrated to decrease within the renewal periods (24 h) to about 0.098 to 0.135 mg/L which corresponds to the approximate level of water solubility (ca. 0.122 mg/L). There was no mortality observed at this concentration. Thus, the LC0 is ca. 0.24 mg/L (averaged geometric means of concentrations at the start and the end of renewal solutions from different time points). The LC50 is reported as > 0.5 mg/L.

There were no effects observed at concentrations within the water solubility of DIPN.

  Table 1: Summary of short-term fish study results with DIPN

Study	Test concentration	Result	Shortcomings	Reliability
Handley/Safepharm 1989 (golden orfe)	nominal: 0.5 mg/L measured: 0 h:  0.55  mg/L 24 h: 0.135 mg/L 96 h: 0.098 mg/L	LC0: ca. 0.24 mg/L (averaged geometric mean for 24 and 96 h) LC50: > 0.5 mg/L (nominal)	only one test concentration; test concentration strongly decreasing over time	2
Kikushima et al. 2003 (killifish)	0.953, 1.71, 3.09, 5.56, 10 mg/L	LC0: 0.95 mg/L LC50: 2.44 mg/L	no information on analytical measurement of TS concentrations; use of vehicle; short renewal period (8 h)	2