Aluminum cobalt oxide

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vitro / ex vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well documented study which meets basic scientific principles.

Data source

Reference

Reference Type:

publication

Title:

Bioaccessibility testing of cobalt compounds

Author:

Stopford, W. et al.

Year:

2003

Bibliographic source:

J. Environ. Monit., 2003, 5, 675–680

Materials and methods

Objective of study:

bioaccessibility (or bioavailability)

Principles of method if other than guideline:

The aim of this study was to measure and compare the bioaccessibility of selected cobalt compounds in artificial human tissue fluids and human serum. A second aim was to initiate studies to experimentally validate an in vitro methodology that would provide a conservative estimate of cobalt bioavailability in the
assessment of dose from human exposure to various species of cobalt compounds.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Cobalt oxide

EC Number:

215-154-6

EC Name:

Cobalt oxide

Cas Number:

1307-96-6

IUPAC Name:

1307-96-6

Details on test material:

- Name of test material (as cited in study report): Cobalt (II) oxide, cobalt monoxide, CoO
- Analytical purity: no data
- Physical characteristics of cobalt monoxide: 78% Cobalt

Radiolabelling:

no

Test animals

Species:

other: in-vitro testing

Strain:

other: in-vitro testing

Administration / exposure

Route of administration:

other: not applicable

Vehicle:

unchanged (no vehicle)

Results and discussion

Bioaccessibility (or Bioavailability)

Bioaccessibility (or Bioavailability) testing results:

The maximum extractable cobalt levels, expressed as a percentage of available cobalt in cobalt monoxide are presented in the following:

Ingestion
Gastric juice (pH 1.5): 100%
Intestinal juice (pH 7.4): 2.1%

Inhalation
Alveolar fluid (pH 7.4): 2.4%
Interstitial fluid (pH 7.4): 9.9%
Serum (pH 7.4): 19.9%
Lysosome fluid (pH 4.5): 92.4%

Cobalt oxide was nearly completely soluble in acid fluids (gastric juice and lysosomal fluid equivalents) but was less than 10% soluble in neutral fluids (intestinal juice, alveolar fluid, interstitial fluid). In serum which is identical to plasma except for the lack of fibrinogen (however the presence or absence of fibrinogen would not be expected to appreciably affect solubility results), cobalt oxide was about 20% soluble.