Calcium dibenzoate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.396 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

3.85 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.396 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

no hazard identified

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

2.04 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

2.04 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

0.176 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

Metal carboxylates are salts consisting of metal cations and carboxylic acid anions. Based on the solubility of calcium dibenzoate in water, a complete dissociation resulting in calcium and benzoate ions may be assumed under environmental conditions. The respective dissociation is in principle reversible and the ratio of the salt /dissociated ions is dependent on the metal-ligand dissociation constant of the salt, the composition of the solution and its pH. However, under environmental conditions, a reunion of the dissociated ions is highly unlikely and it may reasonable be assumed that the respective behaviour of the dissociated calcium cations and benzoate anions in the environment determine the fate of calcium dibenzoate upon dissolution with regard to (bio)degradation, bioaccumulation, partitioning resulting in a different relative distribution in environmental compartments (water, air, sediment and soil) and subsequently its (eco)toxicological potential.

In the assessment of environmental fate and toxicity of calcium dibenzoate, read-across to the assessment entities soluble calcium substances and benzoic acid is applied since the individual ions of calcium dibenzoate determine its environmental fate and toxicity. Since calcium ions and benzoate ions behave differently in the environment, in respect of their fate and toxicity, a separate assessment of each assessment entity is performed. Please refer to the data as submitted for each individual assessment entity.

In order to evaluate ecotoxicological properties of the substance calcium dibenzoate, information on the assessment entities calcium cation and benzoate anion were considered. For a documentation and justification of that approach, please refer to the separate document attached to section 13, namely Read Across Assessment Report for calcium dibenzoate.

Conclusion on classification

Aquatic toxicity studies with calcium dibenzoate are not available, thus aquatic toxicity is addressed with existing data on the dissociation products. Calcium is naturally ubiquitous in the environment. As calcium is essential for normal physiological functioning in species of all trophic levels, e.g. as  body structure-forming element of bones or exoskeletons or electrolyt in physiological liquids, it has a very low potential for toxicity to freshwater and saltwater organisms and adverse effects are lacking up to and including the respective OECD/EC guidelines limit concentrations. The aquatic hazard assessment is based on the most toxic moiety, i.e. the benzoate anion. Existing aquatic toxicity data of benzoic acid are recalculated for calcium dibenzoate based on a maximum benzoate content of 85.8 %.

 

Acute (short-term) toxicity: Reliable acute aquatic toxicity data are available from guideline studies for algae, daphnia, and fish. The lowest EC/LC50 values are 38.6 mg/L, > 116.6 mg/L, and 52.0 mg/L, respectively, and are well above the classification cut-off value for acute (short-term) aquatic hazard category 1. Therefore, calcium dibenzoate does not meet classification criteria as short-term hazard to the aquatic environment under Regulation (EC) No 1272/2008 and its subsequent adaptations.

 

Chronic (long-term) toxicity: Reliable chronic aquatic toxicity data are available from guideline studies for algae, daphnia, and fish. The lowest respective EC10/NOEC values are 3.96 mg/L, 29.1 mg/L, and 139.9 mg/L, respectively, and are well above the classification cut-off values for long-term aquatic hazard category 1 -3 and criteria for classification in category 4 are also not met. Therefore, calcium dibenzoate does not meet classification criteria as long-term hazard to the aquatic environment under Regulation (EC) No 1272/2008 and its subsequent adaptations.