Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The following boron-sorption values are proposed:

Soil: Kp = 2.2 L/kg

Marine Sediment: Kp = 3.0 L/kg

Freshwater Sediment: Kp = 1.94 L/kg

Suspended solids: Kp = 3.5 L/kg.

 

Based on its high water solubility, relatively low sorption value, low vapour pressure, partition coefficients and environmental distribution, boric oxide is considered to be relatively mobile in the environment. Atmospheric boron will wash out via percolating rainwater. Boron in sediments and soils will equilibrate with overlying water or pore-water, with the equilibrium favoring the aqueous phase. Boron may leach or dissolve from solids, but rates will vary depending on the matrix. Non-porous solids will retain boron. Anthropogenic boron releases are mostly from combustion of fuels such as coal; amounts associated with other used of mined borates result in smaller environmental releases. About half the processed boron is used in products that are not likely to release boron to the environment. The oceans are the largest reservoir of boron and sea salt aerosols are likely the largest portion (about 75 %) of the estimated non-anthropogenic releases of boron to the environment, about 2 x 10^9 kg/year.