Naphthalene sulfonic acid, reaction products with isobutanol,sodium salts

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

As the results of this range finding test are considered to be valid and because both test substances are very similar in their fate during the algae test, the conclusion as obtained from this test is considered sufficient to select the more toxic substance as the worst-case representative in the hazard assessment of both substances if the higher toxicity observed for substance 2 is confirmed in an daphnia range finding test.

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
See chapter 13 for more information on the Read across

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

only range finding is performed to compare two substances

GLP compliance:

no

Remarks:

Range finding study to validate read across theory

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test medium Dutch Standard Water (DSW) was used for testing. DSW has a pH approximately 8 and contains: 200 mg of CaCl2•2H2O, 180 mg of MgSO4•7H2O, 100 mg of NaHCO3 and 20 mg of KHCO3.The water was made by an automatic dosing system.
The test substances were found to be readily soluble or dispersible in water and therefore stock solutions of 100 mg/L of test substances were prepared in test media as follows: To an accurately weighed amount of 0.0521 g of the test substances 400 mL of freshly prepared DSW medium was added. The stock solutions were then agitated with a magnetic stirrer until homogeneous solutions were achieved. Both test substances appeared to dissolve easily. pH was checked and was in both cases pH 8.25. The pH was therefore not adjusted. The total volume was then made up to 500 mL for both test chemicals. Clear homogeneous stocks were produced. The appropriate volume of the test substance stocks was then transferred to 100 mL volumetric flasks and further diluted with test media to generate the test concentrations indicated below.

Test organisms (species):

Daphnia magna

Details on test organisms:

The test animals were taken from a Daphnia magna clone 5 stock, (Origin: NOTOX B.V The
Netherlands) cultured in conformity with the relevant SOP. The animals used in the test were less than 24 hours old and were obtained from parent animals reproducing parthenogenically and having an age of 2-4 weeks (having previously produced at least one brood before use). The culture is checked yearly for sensitivity by a reference test with Potassium dichromate. The results of this test were within the range given in the relevant
guideline.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

DSW

Test temperature:

18.8 - 20.1 °C

pH:

8.1 - 8.2

Dissolved oxygen:

8.8 - 8.9 mg/L

Salinity:

DSW

Nominal and measured concentrations:

Standard daphnia screening test concentrations of 0.01, 0.1, 1.0, 10 and 100 mg/L were prepared for both test substances in test media. (nominal)

Reference substance (positive control):

yes

Remarks:

The culture is checked yearly for sensitivity by a reference test with Potassium dichromate. The results of this test were within the range given in the relevant guideline.

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Substance 1

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Substance 2

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Substance 2

Basis for effect:

mobility

Results with reference substance (positive control):

Within the guideline requirements

Reported statistics and error estimates:

-

Test substance 1

 

Concentration (mg/L)	Batches/Total	Number of mobile animals
		0 hours	24 hours	48 hours
Control	Batch I Batch II Total	5 5 10	5 5 10	5 5 10
0.01	Batch I Batch II Total	5 5 10	5 5 10	5 5 10
0.1	Batch I Batch II Total	5 5 10	5 5 10	5 5 10
1.0	Batch I Batch II Total	5 5 10	5 5 10	5 5 10
10.0	Batch I Batch II Total	5 5 10	5 5 10	5 5 10
100.0	Batch I Batch II Total	5 5 10	5 5 10	5 5 10

 

Test substance 2

 

Concentration (mg/L)	Batches/Total	Number of mobile animals
		0 hours	24 hours	48 hours
Control	Batch I Batch II Total	5 5 10	5 5 10	5 5 10
0.01	Batch I Batch II Total	5 5 10	5 5 10	5 5 10
0.1	Batch I Batch II Total	5 5 10	5 5 10	5 5 10
1.0	Batch I Batch II Total	5 5 10	5 5 10	5 5 10
10.0	Batch I Batch II Total	5 5 10	5 5 10	5 5 10
100.0	Batch I Batch II Total	5 5 10	5 5 10	5 3 8

 

 

Validity criteria fulfilled:

yes

Remarks:

for a range finding test

Conclusions:

The daphnia rangefinding test has been performed to evaluate which of both substances tested is the more toxic substance. The results obtained indicate that there is a slightly higher toxicity observed for test substance 2. As the results of this range finding test are considered to be valid and because both test substances are very similar in their fate during the daphnia test the conclusion as obtained from this test is considered sufficient to select the more toxic substance as the worst-case representative in the hazard assessment of both substances if the result obtained is confirmed in an algae range finding test.

Executive summary:

The acute toxicity of two similar substances to daphnia magna was evaluated in a rangefinding test performed according to OECD 202.

For substance 1 ( A complex mixture which includes alkyl naphthalenes, alkyl biphenyls, and alkyl benzenes. low nonene substitution batch no S001235) a NOEC could be calculated of 100 mg/L test substance

For substance 2 (A complex mixture which includes alkyl naphthalenes, alkyl biphenyls, and alkyl benzenes + high nonene alkylation. batch no S001218) a NOEC could be calculated of 10 mg/L test substance.

The results obtained indicate that there is a slightly higher toxicity observed for test substance 2. As the results of this range finding test are considered to be valid and because both test substances are very similar in their fate during the daphnia test, the conclusion as obtained from this test is considered sufficient to select the more toxic substance as the worst-case representative in the hazard assessment of both substances if the higher toxicity observed for substance 2 is confirmed in an algae range finding test.

Description of key information

The acute toxicity of Sodium diisobutylnaphthalenesulphonate to daphnia is read across from the structurally related substance naphthalenesulfonic acid, bis(1-methylethyl)-, methyl derivatives, sodium salts.

In addition acute daphnia rangefinding tests have been performed with two batches of Aromatic Hydrocarbons, C10-13, Reaction Products With Branched Nonene Sulphonated, sodium salt to evaluate which of two relatively similar alkylnaphthalene sulphonates is the more toxic substance. The results obtained indicate that there is a slightly higher toxicity observed for the batch containing a higher fraction of long alkyl chain derivative when compared to the batch with a lower content of long alkyl chain derivative.

Comparable EC50 are observed in the acute daphnia test with naphthalenesulfonic acid, bis(1-methylethyl)-, methyl derivatives, sodium salts and Aromatic Hydrocarbons, C10-13, Reaction Products With Branched Nonene Sulphonated, sodium salt as for both EC50 values are observed of >100 mg/L. The study with naphthalenesulfonic acid, bis(1-methylethyl)-, methyl derivatives, sodium salts is however a complete study and the result as observed for this substance is there use for read across to those alkylnaphthalenesulphonates for which the acute daphnia data are missing.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

In the acute immobilization test with Daphnia magna(STRAUS), the effect of the test item Naphthalenesulfonic acid, bis(1-methylethyl)-, methyl dervis., sodium salt was determined according to OECD 202 (2004).

The test item is a substance of unknown or variable composition (UVCB). Due to the complex nature of the test item for the purposes of the test, the test item was prepared following the protocol of water accommodated fraction (WAF). Since the water solubility of the test item is above the tested limit concentration, the test solution is considered to be true solution at loading level. Therefore, the limit loading will be considered as the actual test item concentration throughout this report.

The study was performed under static conditions over a period of 48 hours with one concentration of the test item prepared as a limit test item concentration of 100 mg/L. All concentrations were visually clear throughout the exposure period and showed no Tyndall effect.

The concentrations of the test item Naphthalenesulfonicacid, bis(1-methylethyl)-, methyl dervis., sodium salt were analytically verified via UPLC-DAD in fresh media at the start of the exposure (0 hours) and the end of the exposure (48 hours) in the limit concentration and the control. Recoveries of the test item were in the range of 99 % at the start and end of exposure.

The measured concentration of the test item was within±20% of the nominal concentration.

In view of substances labeled as UVCB, all terms related to concentration levels should be given as loading levels because partly dissolved compounds and mixtures cannot be related to concentrations. However, since the limit test item concentration is below the certified water solubility and analytical recoveries of the main constituents were within nominal range, the EC_{10 / 50 / 100}- are therefore based on the nominal test item concentration.

 

Effect values	Test duration [hours]	Naphthalenesulfonic acid, bis(1-methylethyl)-, methyl dervis., sodium salt Nominal concentration of the test item [mg/L]
EC10/ EC50/ EC100	24	> 100
	48	> 100