Magnesium perchlorate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Remarks:

in silico, (Q)SAR performed with OECD QSAR Toolbox, Read Across analysis

Type of information:

other: (Q)SAR from supporting substances (structural analogues or surrogates) for which an experimental result is available

Adequacy of study:

key study

Study period:

2019-03-29

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification, with an experimental result (as provided by the OECD QSAR Toolbox)

Justification for type of information:

1. SOFTWARE
OECD QSAR Toolbox v4.3.1

2. MODEL (incl. version number)
Read Across analysis

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
[Mg+2].[O-]Cl(=O)(=O)=O.[O-]Cl(=O)(=O)=O

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
Please refer to 'Attached justification'

5. APPLICABILITY DOMAIN
Please refer to 'Attached justification'

Qualifier:

according to guideline

Guideline:

other: ECHA Guidance R.6

Principles of method if other than guideline:

- Software tool(s) used including version: OECD QSAR Toolbox v4.3.1
- Model(s) used: Read Across analysis
- Model description: see field 'Justification for non-standard information' and 'Attached justification'
- Justification of QSAR prediction: see field 'Justification for type of information' and 'Attached justification'

GLP compliance:

no

Remarks:

Not applicable (QSAR calculation)

Specific details on test material used for the study:

[Mg+2].[O-]Cl(=O)(=O)=O.[O-]Cl(=O)(=O)=O

Test organisms (species):

Daphnia magna

Water media type:

freshwater

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

not applicable

Conclusions:

The short-term toxicity of Magnesium perchlorate to aquatic invertebrates was predicted with OECD QSAR Toolbox v4.3.1 using experimental results of the analogues Potassium perchlorate (CAS 7778-74-7) and Lithium perchlorate (CAS 7791-03-9). Since the perchlorate is considered to trigger the toxicity, this approach is justified. The predicted EC50 (48 h) for Daphnia magna is 100 mg/L (nominal).

In water, Magnesium perchlorate will rapidly dissolve and completely dissociate into the perchlorate anion and the corresponding cation. Toxicity is determined only by the perchlorate moiety of the salt, as magnesium is known to be non-toxic. Based on that fact, it is considered entirely appropriate to use data of related perchlorate salts dissociating in water.

The concentration of 100 mg/L represents the upper limit value for classification as aquatic chronic cat. 3, but taking into account the predicted log Kow of -6.53 Magnesium perchlorate does not need to be classified according to Regulation 1272/2008 and amendments.

Executive summary:

The acute toxicity of Magnesium perchlorate to aquatic invertebrates was predicted with OECD QSAR Toolbox v4.3.1 using experimental results of the analogues Potassium perchlorate (CAS 7778-74-7) and Lithium perchlorate (CAS 7791-03-9). Since the perchlorate is considered to trigger the toxicity, this approach is justified. The predicted EC₅₀ (48 h) for Daphnia magna is 100 mg/L (nominal).

In water, Magnesium perchlorate will rapidly dissolve and completely dissociate into the perchlorate anion and the corresponding cation. Toxicity is determined only by the perchlorate moiety of the salt, as magnesium is known to be non-toxic. Based on that fact, it is considered entirely appropriate to use data of related perchlorate salts dissociating in water.

Description of key information

EC₅₀ (48 h) = 100 mg/L for Daphnia magna (prediction by OECD QSAR Toolbox v4.3.1, 2019; based on experimental results of closely related analogues Potassium perchlorate and Lithium perchlorate)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

The short-term toxicity of Magnesium perchlorate to aquatic invertebrates was predicted with OECD QSAR Toolbox v4.3.1 using experimental results of the closely analogue substances Potassium perchlorate (7778-74-7) and Lithium perchlorate (CAS 7791-03-9). These analogue substances were tested for their short-term toxicity to Daphnia magna according to OECD TG 202 (GLP). Since the perchlorate is considered to trigger the toxicity, this approach is justified.

In water, Magnesium perchlorate will rapidly dissolve and completely dissociate into the perchlorate anion and the corresponding cation. Toxicity is determined only by the perchlorate moiety of the salt, as magnesium is known to be non-toxic. Based on that fact, it is considered entirely appropriate to use data of related perchlorate salts dissociating in water. However, the registrant is prepared to conduct an experimental study but considered it as not necessary at first instance taking into account the available results.

The concentration of 100 mg/L represents the upper limit value for classification as aquatic chronic Cat. 3, but taking into account the predicted log K_owof -6.53 Magnesium perchlorate does not need to be classified according to Regulation (EC) No 1272/2008 and amendments.

This conclusion is supported by the results for the short- and long-term toxicity of the closely analogue substances Ammonium and Sodium perchlorate presented in the publication of Loureiro et al. (2012). Following experimental studies according to OECD TG 202 and OECD TG 211 the 48 h EC₅₀ was determined to be 396.21 mg/L and 3925 mg/L and the 21 d NOEC for reproduction was determined to be 80 mg/L and 110 mg/L for Ammonium and Sodium perchlorate, respectively. Hence, Ammonium and Sodium perchlorate showed to have low hazard for Daphnia magna and a comparable result is expected for the registered substance Magnesium perchlorate when tested in this system.