Reaction mass of 4-sulfophthalic acid and 3-sulfophthalic acid

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Non-GLP guideline study without anayltical monitoring

Justification for type of information:

REPORTING FORMAT FOR THE CATEGORY APPROACH
1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The read across follows Scenario 5 - Qualitatively and quantitatively similar effects are caused by a common compound, which is formed from all category members (as described in the 2017 Read-Across Assessment Framework document).
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
TARGET: Reaction Mass of 4-sulphophthalic acid and 3-sulphophthalic acid (ratio 3:1)
SOURCE: Sulfophthalic acid sodium and ammonium salts
3. CATEGORY APPROACH JUSTIFICATION
Sulphophthalic acid sodium and ammonium salts are different organic salts of a common acid, sulphophthalic acid. The salts dissociate rapidly in the medium (water) to the common sulphophthalic acid anion and to their different counter ions. The counter ions ammonium and sodium do not influence the solubility and the toxicity of the category members
4. DATA MATRIX
See Read Across document attached to CSR

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

no

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Test temperature:

20°C

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

90.8 mg/L

Nominal / measured:

nominal

Basis for effect:

cell number

Validity criteria fulfilled:

yes

Conclusions:

There were no compound related phytotoxic effects, and the 72-hr EC50was determined to be 90.8 mg/L.

Executive summary:

There are no toxicity to aquatic algae and cyanobacteria studies on the reaction mass of 4-sulphophthalic acid and 3-sulphophthalic acid (read across target substance). However, data is available for the reaction mass of 1,2-benzenedicarboxylic acid, 4-sulfo-, trisodium salt, 1,2-benzenedicarboxylic acid, 3-sulfo-, sodium salt (1:3), sodium sulphate (read across source substance) and it was used for read-across purposes. In a 72-hour toxicity study, the cultures of the green algae (Desmodesmus subspicatus) were exposed at nominal concentrations of 0 and 100 mg/L nominal water-accommodated factor (WAF) loading rate under static in accordance with the guideline OECD Guideline 201 (Alga, Growth Inhibition Test). There were no compound related phytotoxic effects, and the 72-hr EC50was determined to be 90.8 mg/L.

Description of key information

There are no toxicity to aquatic algae and cyanobacteria studies on the reaction mass of 4-sulphophthalic acid and 3-sulphophthalic acid (read across target substance). However, data is available for the reaction mass of 1,2-benzenedicarboxylic acid, 4-sulfo-, trisodium salt, 1,2-benzenedicarboxylic acid, 3-sulfo-, sodium salt (1:3), sodium sulphate (read across source substance) and it was used for read-across purposes. In a 72-hour toxicity study, the cultures of the green algae (Desmodesmus subspicatus) were exposed at nominal concentrations of 0 and 100 mg/L nominal water-accommodated factor (WAF) loading rate under static in accordance with the guideline OECD Guideline 201 (Alga, Growth Inhibition Test). There were no compound related phytotoxic effects, and the 72-hr EC50 was determined to be 90.8 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

90.8 mg/L