Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
64 µg/L
Assessment factor:
50
PNEC freshwater (intermittent releases):
0.42 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
6.4 µg/L
Assessment factor:
500

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
497 mg/L
Assessment factor:
1

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
0.61 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
0.061 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:
0.084 mg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

In a stability test in water (van Dam, 2014) at test conditions (pH 8, 20 °C) it was observed that bis(4-methylbenzoyl)peroxide is hydrolytically instable with a half-life of 2.3h. A full hydrolysis study is planned to investigate the speed of hydrolysis at different environmentally relevant pHs and the formation of the main degradation product p-toluic acid (CAS no. 99 -94 -5).

It is technically difficult to obtain test concentrations of the parent substance close to the water solubility limit and to remove the non-dissolved fraction and with such fast hydrolysis, the low water solubility of 43 µg/L and the technical difficulties it should be concluded that tests should be performed with degradation products instead and PNEC values should be determined for this substance.

Conclusion on classification

Bis(4 -methylbenzoyl)peroxide has a harmonized classification:

Directive (67/548/EEC)

R50/53

Regulation (EU) No 286/2011

Aquatic acute 1; H400

Aquatic chronic 1: H410

M-factor for both is 1

UN GHS

Aquatic acute 1; H400

Aquatic chronic 1: H410

M-factor for both is 1

Bis(4 -methylbenzoyl)peroxide is not very soluble in water (43 µg/L) and has a high log Kow of 4.7.

From a ready biodegradability study it can be concluded that the substance is readily biodegradable, besides this it shows very fast hydrolysis. The main degradation product is p-toluic acid (CAS 99 -94 -5) which is also readily biodegradable and has a log Kow of 2.44. This substance shows acute toxicity to invertebrates (most sensitive) with an EC50 of 42 mg/L and a chronic toxicity NOEC of 3.2 mg/L (OECD SIDS, 2008). This substance is therefore not classified.