Bis(D-gluconato-O1,O2)zinc

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

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

Adequacy of study:

key study

Study period:

2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
The read-across hypothesis is instantaneous dissociation of zinc gluconate into zinc cations (Zn2+) and gluconate anions in aqueous media (environmental compartments and body fluids). Thus, for endpoints where no zinc gluconate data exist, the assessment can be based on available data of dissociable zinc compounds and gluconate derivatives.
Considering that the substance is thus composed of two ions: zinc cations (Zn2+) and gluconate anion.
Zinc ion is inorganic, consequently according to the § 9.2.1.1. in column 2, annex VII of REACH the study does not need to be conducted. Only the organic part (gluconate) is relevant.
The experimental study is cited in the OECD SIDS report on gluconic acid and its derivatives. Consequently, the study is considered as reliable since it is from a collection of data made by OECD, an institute well-known for the quality of its bibliographic reviews.
The experimental study was conducted on Sodium D-gluconate as test material. As zinc gluconate, sodium gluconate dissociates in aqueous media into metal ion (sodium) and gluconate anion. Consequently, for the two substances, the same dissociated organic part is present in water media. In the OECD SIDS, the same read-across approach was used to extrapolate this result to other gluconic acid derivatives.
Taking into account the approach provided, the present read-across is considered relevant and reliable.

Ref :
SIDS Initial Assessment Report for SIAM 18: GLUCONIC ACID AND DERIVATIVES 2004.
Orignial experimental study cited: Hydrotox GmbH (2001). Closed bottle test of sodium D-gluconate, according to 92/69/EWG, C.4-E. Study Number 01/1004. Prepared by Hydrotox GmbH, 2001. Unpublished, sponsored by Jungbunzlauer S.A., Marckolsheim, France.

Reason / purpose for cross-reference:

read-across source

Test performance:

No unusual observations during test.

Key result

Parameter:

% degradation (O2 consumption)

Value:

61

Sampling time:

3 d

Remarks on result:

other: meets 10-day window

Parameter:

% degradation (O2 consumption)

Value:

89

Sampling time:

28 d

Remarks on result:

other: maximum degradation

Results with reference substance:

degradation of 67% after 3 days

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The tested substance Sodium D-gluconate is readily biodegradable under tested condition.

Executive summary:

Sodium D-gluconate biodegradation ws investigated under Closed Bottle Test. The tested substance Sodium D-gluconate is readily biodegradable under tested condition. This test is cited and used in the SIDS report on gluconic acid and its derivatives.

Description of key information

The organic part is assess by read-across approach (two compounds with the same dissocitate organic part in media water). The substance is considered readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater