Registration Dossier

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Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.52 mg/L
Assessment factor:
5
Extrapolation method:
sensitivity distribution
PNEC freshwater (intermittent releases):
109 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
41 mg/L

STP

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

Sediment (freshwater)

Hazard assessment conclusion:
no exposure of sediment expected
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:
no exposure of sediment expected
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:
3.2 mg/kg soil dw
Assessment factor:
10
Extrapolation method:
assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Potassium bromide is an inorganic salt that dissociates to its composite ions in aqueous solutions at environmental pH and temperature. Comparison of the available data on the various bromide salts have shown that the bromide ion is the relevant ion for determination of the toxicological profile with simple cations such as potassium, sodium or ammonium, that are ubiquitous in nature, having little or no influence on the bromide ion properties. It is therefore justified to read-across data from other inorganic bromide salts to potassium bromide.

It is not considered justified to combine the datasets for marine and freshwater organisms because of the following:

Reported concentrations of bromide in freshwater are between 0.02 to 0.27 mg Br-/L, while for marine waters a range of 41 to 71 mg Br-/L is reported (Flury and Papritz, 1993). It is not clear whether the data of Flury and Papritz (1993) always refer to undisturbed areas, but at least the seawater data are expected to represent natural background concentrations. Cooper et al. (2007) cite Br- levels of 67 mg Br-/L at 35 ‰ salinity. Due to the adaptation to saline environments and higher bromide levels, marine organisms may react differently towards inorganic bromide salts as compared to freshwater organisms. It cannot be predicted beforehand whether the adaptation to higher salinities results in a lower or higher tolerance towards Br-. The available data for Artemia salina and Skeletonema costatum indicate that these marine species are more sensitive than their freshwater relatives. It is

possible that, although higher levels of Br- are tolerated, the capacity to regulate ion concentrations is sensitive towards relatively small changes in the total ion balance. Toxicity data for freshwater and marine species are kept separated for PNEC-derivation.

The ecotoxicological information was gathered via experimental studies including acute and chronic studies. The NOEC values obtained from the studies were used for calculation of the various PNEC values. 

Conclusion on classification

Potassium bromide is not classified for the environment based on the read-across to data for sodium bromide.