reaction mass of: tetrasodium 7-(4-(4-fluoro-6-(4-(2-sulfonatoethylsulfonyl)phenylamino)-1,3,5-triazin-2-ylamino)-2-ureidophenylazo)naphthalene-1,3,6-trisulfonate;tetrasodium 7-(4-(4-hydroxy-6-(4-(2-sulfonatoethylsulfonyl)phenylamino)-1,3,5-triazin-2-ylamino)-2-ureidophenylazo)naphthalene-1,3,6-trisulfonate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 June 1998 to 19 June 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to recent EU test guidance in compliance with GLP.

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable.

Analytical monitoring:

no

Details on sampling:

- Concentrations: 25, 50 & 100 mg/L

Vehicle:

no

Details on test solutions:

Stock solution in accordance with Laboratory SOP 2030-6600401-96. No other details provided

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Species: Scenedesmus subspicatus CHODAT
Origin: Cultivation (stock cultures, precultures, test cultures) Institute of Plant Physiology, University of Gottingen. In a light chamber at 23 ± 2 °C and with a guantum flux which eguals 120 /iE/m2 -s.
Water for dilution: deionized water

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

No post exposure obsveration

Hardness:

No data

Test temperature:

No data

pH:

8.5

Dissolved oxygen:

No data

Salinity:

No data

Nominal and measured concentrations:

25, 50, 100 mg/L

Details on test conditions:

Test procedure -Erlenmeyer flasks (300 mL) with stoppers
-100 ml of test medium
-light chamber and magnetic stirrer
-Determination of the effects on the growth of Scenedesmus subspicatus within a 72 h exposure period.
Counting: Microcellcounter Sysmex F-300 Digitana (SOP 2030-0001903-98 D)
Method of administration: stock solution (SOP 2030-6600401-96 D) (125 mg/L)
Test concentration/s [mg/L]: 25, 50, 100
Solubilizer or other auxiliaries: none
Inoculum: Algal suspension taken from an exponentially growing preculture which serves to adjust an initial cell density of 10 000 cells per millilitre.
Control: Inoculum in nutrient medium and water for dilution.
Water for dilution: deionized water

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 22.5 - < 43.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 43.5 - < 87 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 43.5 - < 87 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 87 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

22.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

cell number

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

43.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

cell number

Details on results:

The test results refer to concentrations of the test substance which were calculated directly from analytically determined TOC values. If the test substance had a high purity degree, f.e. 95 % which is the upper limit of the content of the main component, 1 mg/L TOC would egual to 3 mg/L of the test substance. As the mean content of the main component is only 60.2 % and as there is nothing known about the identity and percentage of the organic byproducts, TOC values merely reflect constant exposure conditions of the sum of all C-containing components during the test. In summary, the above numerical results are based on the equation "TOC x 3 = test substance" (which is only valid for high purity degrees of Reaktiv-Gelb FD 08064).

Results with reference substance (positive control):

Not applicable.

Reported statistics and error estimates:

The above test results refer to concentrations of the test substance which were calculated directly from analytically determined TOC values.
If the test substance had a high purity degree, f.e. 95 % which is the upper limit of the content of the main component, 1 mg/L TOC would egual to 3 mg/L of the test substance. As the mean content of the main component is only 60.2 % and as there is nothing known about the identity and percentage of the organic byproducts, TOC values merely reflect constant exposure conditions of the sum of all C-containing components during the test. In summary, the above numerical results are based on the eguation "TOC x 3 = test substance"

It should be noted that under the current REACH regulation for which this registration is being made, there have been some alterations to the manner in which Algal data is interpreted. It is known that the following is applicable:

 

1. In algal studies, the result based on growth rate shall be used for evaluation instead of those for biomass. Thus, the result of the algae study is ErC50 >87 mg/L (measured). However there is no reason to recalculate nominal concentrations with measured concentrations as long as the result of the analytical monitoring is >80% of the nominal concentration. For this reason, the actual result which should be reported within this registration under REACH should be ErC50 >100 mg/L (nominal).

2. The decrease of  growth rate at the highest concentration (87/100 mg/L) was given as 23%. A further examination of the probit analysis has been undertaken by an independent consultant whom has extrapolated the original values with ToxRat (version 2.10.05), Weibull distribution.

 

The results of this assessment are as follows:

Based on nominal concentrations: ErC50 = 175 mg/L (95%CV: lower 145 mg/L, higher 253 mg/L).
Based on measured concentrations: ErC50 = 152 mg/L (95%CV: lower 125 mg/L, higher 221 mg/L).

 

As such it is proposed that the current classification R52/R53, on the basis of the original algal results is no longer applicable. The classification detailed in Section 2 of this registration dossier indicate this required revision.

 

Validity criteria fulfilled:

yes

Conclusions:

Toxicity to algae (mg/L):
Exposure time : 72 h
Growth (integral of biomass): Growth rate
EC 10 : > 22,5 < 43,5 EC 10 : > 43,5 < 87,0
EC 50 : > 43,5 < 87,0 EC 50 : > 87,0
Dunnett test:
NOEC : 22,5
LOEC : 43,5

Probit analysis has been undertaken by an independent consultant whom has extrapolated the original values with ToxRat (version 2.10.05), Weibull distribution. The results of this assessment are as follows:

Based on nominal concentrations: ErC50 = 175 mg/L (95%CV: lower 145 mg/L, higher 253 mg/L).
Based on measured concentrations: ErC50 = 152 mg/L (95%CV: lower 125 mg/L, higher 221 mg/L).

The test results indicate no hazard potential against algae.

Executive summary:

Study conducted to EU test guidance 92/69/EEC part C3 in compliance with GLP.

Based on the revised guidance associated with REACH, probit analysis has been undertaken by an independent consultant whom has extrapolated the original values with ToxRat (version 2.10.05), Weibull distribution. The results of this assessment are as follows:

Based on nominal concentrations: ErC50 = 175 mg/L (95%CV: lower 145 mg/L, higher 253 mg/L).
Based on measured concentrations: ErC50 = 152 mg/L (95%CV: lower 125 mg/L, higher 221 mg/L).

The substance has no hazard potential against algae.

Description of key information

The results of the original study have been reviewed, and it has been determined that the EC50 values are > 100 mg/L.  As such, the classification of R52/R53  proposed in the original notification under the Seventh Amendment is no longer applicable.

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

It should be noted that under the current REACH regulation for which this registration is being made, there have been some alterations to the manner in which Algal data is interpreted. It is known that the following is applicable:

 

1. In algal studies, the result based on growth rate shall be used for evaluation instead of those for biomass. Thus, the result of the algae study is ErC50 >87 mg/L (measured). However there is no reason to recalculate nominal concentrations with measured concentrations as long as the result of the analytical monitoring is >80% of the nominal concentration. For this reason, the actual result which should be reported within this registration under REACH should be ErC50 >100 mg/L (nominal).

2. The decrease of  growth rate at the highest concentration (87/100 mg/L) was given as 23%. A further examination of the probit analysis has been undertaken by an independent consultant whom has extrapolated the original values with ToxRat (version 2.10.05), Weibull distribution.

 

The results of this assessment are as follows:

Based on nominal concentrations: ErC50 = 175 mg/L (95%CV: lower 145 mg/L, higher 253 mg/L).
Based on measured concentrations: ErC50 = 152 mg/L (95%CV: lower 125 mg/L, higher 221 mg/L).

 

As such it is proposed that the current classification R52/R53, on the basis of the original algal results is no longer applicable. The classification detailed in Section 2 of this registration dossier indicate this required revision.