Registration Dossier

Administrative data

Link to relevant study record(s)

Description of key information

Toxicokinetic data are taken from published authoritative reviews and published data  

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential
Absorption rate - oral (%):
50
Absorption rate - dermal (%):
5
Absorption rate - inhalation (%):
100

Additional information

The International Commission for Radiation Protection (ICRP) estimates that the gastrointestinal absorption of barium is 20% in adults, 30% for children aged 1–15 years, and 60% in infants. In humans, barium is predominantly found in bone; approximately 90%. Approximately 1–2% of the total body burden was found in muscle, adipose, skin, and connective tissue. Barium is not metabolized in the body, but it may be transported or incorporated into complexes or tissues. Faeces is the primary route of excretion following exposure.

Boron is absorbed across pulmonary tissues into the blood. Boron is almost completely absorbed in the gastrointestinal tract (92 -95%). Boron was found to be minimally absorbed across intact human or animal skin. Boron is distributed readily to all body tissues. Boron is a trace element and is not metabolized in the body. Borates exist in the body as boric acid, the only form of boron recovered in the urine. Excretion of systemically absorbed boron is accomplished primarily through renal elimination, with minor fractions excreted in the saliva, sweat, and faeces.

Based on the chemical nature of the substance, it is predicted to dissociate into its constituent ions under physiological conditions and prior to absorption; these ions will be subject to different rates of absorption therefore default assumptions regarding the extent of absorption of the substance are made.