Calcium dihydroxide precipitated with carbon dioxide during sugar juice purification

Toxicity to soil macroorganisms except arthropods

Description of key information

No studies on SFL are available.
The key study was conducted on an analogous substance and assessed the acute toxicity of calcium carbonate (nano) to the earthworm Eisenia foetida in a GLP artificial soil test performed in accordance with OECD Guideline 207. The 14 day LC50 value was >1000 mg/kg and the NOEC was 1000 mg/kg.
The result from this study demonstrates that calcium carbonate is not acutely toxic to earthworms and can be read across to SFL.

Additional information

Acute Toxicity:

Rationale for read across:

SFL is primarily composed of inorganic substances. The major constituent is calcium carbonate, along with silicon dioxide and a small amount of other inorganic salts (including calcium salts) and the remainder is composed of organic plant material. None of the components of SFL carry a classification for physical chemical properties or the environment and therefore SFL is not classified as hazardous to the environment. Since the major component of SFL is calcium carbonate, it can therefore be assumed that the properties of SFL will be governed by those of calcium carbonate. It is therefore considered appropriate for this data to be used for read-across purposes and any further testing would be scientifically unjustified.

The key study for short term toxicity [Goodband (2010a)] was performed to OECD Guideline 207 and in accordance with GLP and was therefore assigned a reliability of 1.The study assessed the acute toxicity of calcium carbonate (nano) to Eisenia foetida in a limit test. There were no significant mortalities or sub-lethal effects observed as a result of exposure to calcium carbonate (nano) at a concentration of 1000 mg/kg in soil. Hence, the 14 day LC50 value was >1000 mg/kg and the NOEC was 1000 mg/kg. Calcium carbonate is therefore not toxic to earthworms up to a concentration of 1000 mg/kg.

Since this study can be read across to SFL, it is expected that SFL would also not be acutely toxic to earthworms.

Long Term Toxicity:

SFL is primarily composed of inorganic substances (the major constituent is calcium carbonate, along with silicon dioxide and a small amount of other inorganic salts) and the remainder is composed of organic plant material. SFL is not classified as harmful or toxic to the environment. The inorganic portion of SFL and the organic plant material are composed of substances which are naturally occurring in the environment. Hence, terrestrial organisms including invertebrates are constantly exposed to the components of SFL without suffering from any adverse or detrimental effects.

SFL is also applied to soil as a fertiliser for the purpose of improving the condition of the soil by guaranteeing an adequate supply of calcium to plants.

Furthermore, an acute toxicity study to earthworms was performed according to OECD 207 as a limit test with a calcium carbonate (nano) concentration of 1000 mg/kg soil [Goodband (2010a)]. There were no significant mortalities or sub-lethal effects of exposure in 60 earthworms exposed to calcium carbonate (nano) for a period of 14 days. As a result, calcium carbonate is considered not acutely toxic to earthworms. This result is considered to be relevant to SFL based on the fact that SFL is primarily composed of calcium carbonate and other calcium salts and hence the properties of SFL are governed by those of calcium carbonate. It can therefore be assumed that SFL is not acutely toxic to earthworms and hence long term testing is considered to be unnecessary.

Given the extensive and continued use of SFL as a constituent of fertiliser and the natural occurrence of its components in the environment, it is considered that SFL would not have a detrimental effect on soil macroorganisms. Therefore, the performance of long term toxicity tests on terrestrial organisms is scientifically unjustified.