3-hydroxy-2'-methyl-2-naphthanilide

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-11-08 to 2009-11-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: study performed according to current guideline and GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

3-hydroxy-2'-methyl-2-naphthanilide

EC Number:

205-205-0

EC Name:

3-hydroxy-2'-methyl-2-naphthanilide

Cas Number:

135-61-5

Molecular formula:

C18H15NO2

IUPAC Name:

3-hydroxy-N-(2-methylphenyl)naphthalene-2-carboxamide

Constituent 2

Reference substance name:

Naphtol AS-D

IUPAC Name:

Naphtol AS-D

Details on test material:

- Name of test material (as cited in study report): Naphtol AS-D
- Molecular formula: C18H15NO2
- Molecular weight: 277.33 g/mol
- Physical state: Solid, beige powder

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: The saturated solution and the control were analytically verified via HPLC in the fresh media (0 hours) and in the old media (48 hours).
- Sampling method: For the old media, separate replicates without test organisms were prepared and incubated under test conditions. The recovery rates of the test item should be ± 20 % of the initially measured. Otherwise the effect levels have to be given based on the geometric mean measured concentration.
- Sample storage conditions before analysis: All samples were stored at 6 ± 2 °C until start of analysis, if necessary.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution (100 mg/L) was prepared with dilution water two days prior to application.
- Dispersion treatment: The stock solution was shaken with 20 rpm for 48 hours (rotating shaker 3040, GFL). Undissolved particles were removed by membrane filtration (membrane filter 0.45 µm, RC, MACHEREY-NAGEL).
- Eluate: Dilution water
- Differential loading: Limit concentration: Saturated solution, corresponding to a geometric mean measured test item concentration of 0.108 mg/L.
- Controls: Dilution water without test item tested under the same conditions as the test groups.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna (STRAUS)
- Strain: Clone 5
- Source: Institut für Wasser-, Boden- Lufthygiene (WaBoLu), further own breeding
- Age at study initiation (mean and range, SD): 2 to 24 h
- Method of breeding: In 2-3 L glass vessels with appr. 1.8 L culture medium, at 20 +/- 2 °C, in an incubator, 16 h illumination, illumination strength max. 20 µExm-2 x s-1
- Feeding during test: No feeding

ACCLIMATION
- Acclimation period: 2 h
- Acclimation conditions (same as test or not): Same as test
- Type and amount of food: No feeding
- Health during acclimation (any mortality observed): Healthy, no mortality observed

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

No

Test conditions

Hardness:

Dilution water at test start: 263 (mg CaCO3/L)

Test temperature:

20.5 °C

pH:

Water Quality Parameters at Test Start (0 hours, New Media)
(measured in one additional replicate of the limit concentration and control)
pH-Value
Saturated solution 7.42
Control 7.98

Water Quality Parameters at Test End (48 hours, Old Media)
(measured in all replicates)
pH-Values
Replicates
1 2 3 4
Saturated solution 7.56 7.57 7.57 7.56
Control 7.47 7.51 7.51 7.53

Dissolved oxygen:

Water Quality Parameters at Test Start (0 hours, New Media)
(measured in one additional replicate of the limit concentration and control)
Dissolved O2 - Concentration

[mg/L]
Saturated solution 7.67
Control 8.37

Water Quality Parameters at Test End (48 hours, Old Media)
(measured in all replicates)
Dissolved O2 - Concentration [mg/L]
Replicates
1 2 3 4
Saturated solution 7.18 7.48 7.44 7.35
Control 7.32 7.27 7.49 7.47

Salinity:

Freshwater

Nominal and measured concentrations:

Please refer to "Any other information on materials and methods"

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers, 50 mL
- Type (delete if not applicable): closed with parafilm
- Material, size, headspace, fill volume: Glass beakers (4 cm ID x 7 cm H), 50 mL
- Aeration: No
- Renewal rate of test solution (frequency/flow rate): One application at test start, static test
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): None


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Acc. to Directive 92/69/EEC Method C.2, Annex 1
- Conductivity: Dilution water at test start: 640 µS/cm
- Culture medium different from test medium: Elendt M4 acc. to ELENDT (1990), modified to a total hardness of 160 to 180 mg CaCO3/L
- Intervals of water quality measurement: At test start and test end


OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16:8 light:dark cycle
- Light intensity: Diffuse light, illumination strength max. 20 µE x m-2 x s-1


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :


TEST CONCENTRATIONS
- Spacing factor for test concentrations: None, limit test
- Range finding study
Immobilization Rates of the Preliminary Range Finding Test [%]
(n = 20, divided into 2 replicates with 10 daphnids each)
Nominal Loading
of the
Saturated Solution
[mg/L] IMMOBILIZATION [%]
24 hours 48 hours
Replicates Replicates
1 2 MV 1 2 MV
100 0 0 0 0 10 5
Control 0 0 0 0 0 0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.108 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: None
- Mortality of control: 0%
- Other adverse effects control: None
- Abnormal responses: None
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: None

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50/LC50: 1.67 (CI 1.63 - 1.71) mg/L

Reported statistics and error estimates:

The effects of the saturated solution were evaluated directly from the observation data.

Any other information on results incl. tables

Percentage of Daphnids Incapable of Swimming after 24 and 48 h of Exposure

                  (n = 20, divided into 4 replicates with 5 daphnids each)

IMMOBILIZATION [%]
Naphtol AS-D Geometric Mean Measured Concentration [mg/L]	24 hours					48 hours
	Replicates					Replicates
	1.	2.	3.	4.	MV	1.	2.	3.	4.	MV
0.108 (Saturated solution)	0	0	0	0	0	0	0	0	0	0
Control	0	0	0	0	0	0	0	0	0	0

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

At the saturated solution of the test item Naphtol AS-D with a nominal loading of 100 mg/L, corresponding to a geometric mean measured concentration of 0.108 mg/L, no effect to Daphnia magna was observed.

Executive summary:

In the acute immobilization test with Daphnia magna (STRAUS) the effects of the saturated solution of the test item Naphtol AS-D with a nominal loading of 100 mg/L as limit concentration were determined according to OECD 202 (2004). The limit test was conducted under static conditions over a period of 48 hours.

EC-Values, NOEC and LOEC

(based on the geometric mean measured test item concentration)

	Test Duration [h]	Geometric Mean Measured Test Item Concentration [mg/L]	Confidence Interval p = 95% [mg/L]
EC50	24	> 0.108	not applicable
	48	> 0.108	not applicable
EC100	24	> 0.108	---
	48	> 0.108	---
NOEC	48	0.108	---
LOEC	48	> 0.108	---

At the saturated solution of the test item Naphtol AS-D
with a nominal loading of 100 mg/L,
corresponding to a geometric mean measured concentration of 0.108 mg/L,
no effect to Daphnia magna was observed.