Registration Dossier

Environmental fate & pathways

Additional information on environmental fate and behaviour

Administrative data

Endpoint:
additional information on environmental fate and behaviour
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:

Data source

Materials and methods

Results and discussion

Applicant's summary and conclusion

Conclusions:
In accordance with REACH Annex XI, the identification of degradation products study (required in section 9.2.3) does not need to be conducted as 'Activated carbon' is a glassy material. It is not soluble in water and has a particle size between 0.5 to >0.5 µm. Therefore it is not expected to pass cell membranes to become accessible for enzymatic attack and thus enzymatic oxidation. But furthermore, the oxidation (mineralisation) of organic substances is accomplished by electron transfer from the electron donor (substance) to the electron acceptor. During biological substrate oxidation, mostly two electrons are transferred at the time, and two protons (H+) are split from the substrate (dehydrogenation). The hydrogen is transferred to NAD or NADP (acceptor) as part of the respiration chain (e.g., citric acid cycle). The substance activated carbon does not contain any hydrogen available for dehydrogenation; thus there is no energy gain by enzymatic dehydrogenation, so further biodegradation of this molecule will not occur. Therefore a test on the biodegradability is scientifically not justified.
Executive summary:

In accordance with REACH Annex XI, the identification of degradation products study (required in section 9.2.3) does not need to be conducted as 'Activated carbon' is a glassy material. It is not soluble in water and has a particle size between 0.5 to >0.5 µm. Therefore it is not expected to pass cell membranes to become accessible for enzymatic attack and thus enzymatic oxidation. But furthermore, the oxidation (mineralisation) of organic substances is accomplished by electron transfer from the electron donor (substance) to the electron acceptor. During biological substrate oxidation, mostly two electrons are transferred at the time, and two protons (H+) are split from the substrate (dehydrogenation). The hydrogen is transferred to NAD or NADP (acceptor) as part of the respiration chain (e.g., citric acid cycle). The substance activated carbon does not contain any hydrogen available for dehydrogenation; thus there is no energy gain by enzymatic dehydrogenation, so further biodegradation of this molecule will not occur. Therefore a test on the biodegradability is scientifically not justified.