Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
no data available: testing technically not feasible

Marine water

Hazard assessment conclusion:
no data available: testing technically not feasible

STP

Hazard assessment conclusion:
no data available: testing technically not feasible

Sediment (freshwater)

Hazard assessment conclusion:
no data available: testing technically not feasible

Sediment (marine water)

Hazard assessment conclusion:
no data available: testing technically not feasible

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
10 mg/kg soil dw
Assessment factor:
100
Extrapolation method:
assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

PNECs for sediment, STP and water environments cannot be provided as the high insolubility of the test substance renders testing unfeasible.

Because the substance is highly insoluble in water, no toxic effects on organisms in water are expected, nor for soil microorganisms or soil plants (exposure through soil interstitial water). To further ensure that there are no effects related to oral intake, a long-term reproduction test with earthworms was performed with the substance Activated Carbon – High Density Skeleton (AC - HDS). This study, resulting in a NOEC of 1000 mg/kg dw, is read across to this dossier with Activated Carbon - Low Density Skeleton (AC - LDS) and is also used in the derivation of PNECsoil. As no data for aquatic organisms are available, an additional calculation of the PNEC using the Equilibrium Partitioning Method cannot be carried out.

The substance has a low potential for bioaccumulation because the substance has no log Kow (substance is an inorganic substance or can be considered to behave as an inorganic substance). Also the substance size will hamper passing membranes as the substance consists of particles with sizes ranging from approximately 0.5 to >0.5 µm. The particles are not soluble in water.

Read Across

The read across is built with activated carbon substances described as porous amorphous high surface area substances composed largely of elemental carbon. These consist of Activated Carbon – High Density Skeleton (AC - HDS) and Activated Carbon - Low Density Skeleton (AC - LDS). Both substances consist of >80% carbon. The mentioned activated carbon substances can be considered as one because they consist of a porous amorphous high surface area substance composed largely of elemental carbon. Differences are related to the skeleton density, which is either high or low.

 

These sustances and its two members can be considered robust among others because they are composed of the same substance (elemental carbon) in the form of activated carbon substances with a porous amorphous high surface area. The only differences are related to skeleton density and the presence of impurities. The substances share their CAS number.

 

Both substances are solid at room temperature, have a water solubility <0.1 mg/L and they have an expected melting point > 1000 degrees C. They are not highly flammable. The particle size is > 0,3 µm. The relative density with 1.67 and 2.31 g/cm3 is comparable.

 

Activated carbon is a refractory material and not amenable to break down by any natural chemical or enzymatic processes. AC is only broken down under extreme conditions - such as heating under reflux with concentrated sulphuric acid/nitric acid mixtures - when the carbon will eventually oxidise to CO2.

 

Rationale & experimental data

Except for soil, no ecotoxicity data are available. However, AC - HDS and AC - LDS being highly insoluble, tests can be waived for aquatic toxicity. Also for uptake by plants and microorganisms, the substance needs to go into solution (interstitial or pore water) before exposure can occur, testing seems irrelevant. Taking into account the structural similarity between AC - HDS and AC - LDS, it can be expected that the result will be similar for both substances. Therefore, the results of this study with AC - HDS will be read-across to AC - LDS.

 

Possible impact of impurities

'Activated carbon' is an amorphous material. It is not soluble in water and has a particle size > 0,3 µm. Therefore, it is expected that the material is not able to pass membranes. This would make the presence of any impurities in the material irrelevant. Also when looking into detail in the impurities based on classification, no impact of the impurities is expected. It is concluded that no impact of impurities is to be expected.

 

Conclusion on classification

Based on the available data and information, the substance does not need to be classified.