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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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 mg/L
Assessment factor:
50
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
0 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0 mg/L
Assessment factor:
500
Extrapolation method:
assessment factor

STP

Hazard assessment conclusion:
no emission to STP expected

Sediment (freshwater)

Hazard assessment conclusion:
no exposure of sediment expected

Sediment (marine water)

Hazard assessment conclusion:
no exposure of sediment expected

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
0.002 mg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential to cause toxic effects if accumulated (in higher organisms) via the food chain

Additional information

Data are available from one acute Daphnia magna study directly as well as read-across from the category for acute fish and algae. All species tested had the same sensitivity (no toxicity at limit of water solubility). One older 21-day chronic study with Daphnia magna was completed with nominal concentrations, closed exposure vessels and renewal every 48 hours. No toxicity was seen by any species at limit of solubility. Because the Daphnia chronic study was reported based on nominal concentrations, the potential for maintaining PTBA in solution between renewals was evaluated. It was found that sufficient PTBA was added to the test chambers and allowed to mix for an appropriate amount of time thus allowing the media and headspace to become saturated with PTBA . The saturation concentration would be maintained for at least 48 hours since the test vessels were sealed. PTBA showed no effect on reproduction at the limit of solubility in media. The solubility limit of PTBA in Daphnia media was found to be 0.0.00071 mg/L from the Daphnia magna acute studies conducted in 2012. Therefore, the chronic Daphnia NOEC (reproduction and survival) is 0.00071 mg/L. Because data from three acute studies are available as well as chronic data from two studies, where the most sensitive acute species was also evaluated for chronic toxicity, an application factor of 50 was used to derive the freshwater PNEC.

Conclusion on classification

Hazardous to the aquatic environment - acute/short-term: conclusive but not sufficient to classify. No acute toxicity at the limit of water solubility.

Hazardous to the aquatic environment - long-term: conclusive but not sufficient to classify. Not chronically toxic at limit of water solubility. Not persistent in aquatic environment.

M-factor chronic: not applicable.

Hazardous to the ozone layer: conclusive but not sufficient to classify. PTBA is not listed in the Montreal Protocol on Substances that Deplete the Ozone Layer. It does not contain reactive halogens (chlorine or bromine) that could play a role in ozone depletion. PTBA is not hazardous to the ozone layer.

DSD endpoints environment: not classified. No acute toxicity at the limit of water solubility. Not persistent in the aquatic environment.