Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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:
0.042 mg/L
Assessment factor:
1 000
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
0.42 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.004 mg/L
Assessment factor:
10 000
Extrapolation method:
assessment factor

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
9.7 mg/L
Assessment factor:
10
Extrapolation method:
assessment factor

Sediment (freshwater)

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

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
0.019 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:
0.014 mg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

1,5,2,4-dioxadithiane 2,2,4,4-tetraoxide (MMDS) is rapidly hydrolised into methandisulphonic acid (MDSA) and formaldehyde in water. Within 104 minutes, all MMDS was hydrolized into MDSA and formaldehyde. As a result of this, it is very difficult to prepare the test solution of MMDS. Therefore, according to the OECD guidance document, No.23, September 2000, "Guidance Doccument of Aquatic Toxicity testing of Difficult Substances and Mixtures", the toxicity studies in algae, Daphnia magna and fish were conducted with MDSA.

As the hydrolysis product MDSA is environmentally more relevant than the registration substance, the PNECs are derived for MDSA.

Formaldehyde is not classified for environmental hazard and thus it was decided not to derive PNECs for this hydrolysis product.

Conclusion on classification

Based on the results of the toxicity studies with the hydrolysis product MDSA on algae, Daphnia magna and fish, and the lack of conclusive data on the degradability of MDSA, the substance MDSA is classified as dangerous for the environment with the risk phrases - "R52 -53 - Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment.", according to Directive 67/548/EEC and as Chronic Category 3 with the hazard statement "H412 - Harmful to aquatic life with long lasting effects" in accordance with Regulation (EC) No. 1272/2008. According to both regulations, the substance is regarded as being not rapidly degradable even though it is deemed acceptable that MDSA will degrade significantly (see discussion in section 5.2).

It is recognized that the environmental Cl&L of the registered substance is based on test data of its hydrolysis product MDSA, but as the hydrolysis is taking place so rapidly (in 104 minutes) and formaldehyde is not considered to be environmentally relevant, this is concluded to be a valid approach.