Reaction mass of zinc oxide and zinc peroxide

Toxicity to aquatic plants other than algae

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic plants other than algae

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The target substance Zinc peroxide and the source substances Zinc oxide, Zinc Chloride, Zinc sulfate, Zinc nitrate are ionic and consist of the Zinc2+ cation and the respective anion.
The read-across is based on the assumption that the zinc cation (as measure for dissolved zinc species) is the determining factor for (eco)toxicity.
For further details, see Justification for read-across attached to IUCLID chapter 13

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See Justification for read-across attached to IUCLID chapter 13

3. ANALOGUE APPROACH JUSTIFICATION
See Justification for read-across attached to IUCLID chapter 13

4. DATA MATRIX
See Justification for read-across attached to IUCLID chapter 13

Reason / purpose for cross-reference:

read-across: supporting information

Reason / purpose for cross-reference:

read-across source

Duration:

3 d

Dose descriptor:

NOEC

Effect conc.:

60 µg/L

Nominal / measured:

nominal

Conc. based on:

dissolved

Basis for effect:

growth rate

Description of key information

chronic NOEC for one multicellular algae species available (0.06mg Zn/l). 
Additional supportive information on 4 higher aquatic plant species available; chronic NOEC >650µg Zn/l on all 4 species tested. 

Additional information

The EU risk assessment on zinc (ECB 2008) used one chronic NOEC on Cladophora glomerata in the PNEC database. Additional information on long term experiments on 4 higher aquatic plant species was used as supportive evidence, demonstrating the low sensitivity of this taxonomic group.