Registration Dossier

Diss Factsheets

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
basic toxicokinetics in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study without detailed documentation
Justification for type of information:
experimental data made available by ECHA
Objective of study:
other: Assessment of toxicokinetic behaviour
Qualifier:
according to guideline
Guideline:
other: as mentioned below
Principles of method if other than guideline:
Assessment of toxicological behavior
GLP compliance:
not specified
Details on absorption:
Acute and sub-chronic inhalation studies and an acute oral toxicity showed no evidence of systemic toxicity. The effects seen in the inhalation studies were attributable to local effects in the lung and upper respiratory tract. Although the molecular weight does not preclude absorption, the substance has very low solubility in water and organic solvents. In view of this low solubility and the toxicity
study results, it is unlikely that any significant systemic absorption of this substance would occur, although transport of sufficently small fibres, by phagocytic cells, into the
lymphatic circulation is a possibility.
Details on distribution in tissues:
Since it is unlikely that any significant absorption could occur, discussion of distribution, metabolism and excretion is largely irrelevant for this inorganic substance. Fibres entering the lymphatic system would be unlikely to dissolve and become bioavailable due to the very low solubility. These factors may, however, result in biopersistence of fibres deposited in the respiratory tract.
Details on excretion:
Since it is unlikely that any significant absorption could occur, discussion of distribution, metabolism and excretion is largely irrelevant for this inorganic substance. Fibres entering the lymphatic system would be unlikely to dissolve and become bioavailable due to the very low solubility. These factors may, however, result in biopersistence of fibres deposited in the respiratory tract.

The test chemical is majorly available in the form of fibre. Its fibrous nature indicates that inhalation exposure would be possible and this is the most relevent route of exposure. The substance is stable so exposure to degradents would not be expected.

Conclusions:
The test chemical is majorly available in the form of fibre. Its fibrous nature indicates that inhalation exposure would be possible and this is the most relevent route of exposure. The substance is stable so exposure to degradents would not be expected.
Executive summary:

Absorption:

Acute and sub-chronic inhalation studies and an acute oral toxicity showed no evidence of systemic toxicity. The effects seen in the inhalation studies were attributable to local effects in the lung and upper respiratory tract. Although the molecular weight does not preclude absorption, the substance has very low solubility in water and organic  solvents. In view of this low solubility and the toxicity study results, it is unlikely that any significant systemic absorption of this substance would occur, although transport of sufficently small fibres, by phagocytic cells, into the lymphatic circulation is a possibility.

Distribution, Metabolism,Excretion

Since it is unlikely that any significant absorption could occur, discussion of distribution, metabolism and excretion is largely irrelevant for this inorganic substance. Fibres entering the lymphatic system would be unlikely to dissolve and become bioavailable due to the very low solubility. These factors may, however, result in biopersistence of fibres deposited in the respiratory tract.

Description of key information

Absorption:

Acute and sub-chronic inhalation studies and an acute oral toxicity showed no evidence of systemic toxicity. The effects seen in the inhalation studies were attributable to local effects in the lung and upper respiratory tract. Although the molecular weight does not preclude absorption, the substance has very low solubility in water and organic  solvents. In view of this low solubility and the toxicity study results, it is unlikely that any significant systemic absorption of this substance would occur, although transport of sufficently small fibres, by phagocytic cells, into the lymphatic circulation is a possibility.

Distribution, Metabolism,Excretion

Since it is unlikely that any significant absorption could occur, discussion of distribution, metabolism and excretion is largely irrelevant for this inorganic substance. Fibres entering the lymphatic system would be unlikely to dissolve and become bioavailable due to the very low solubility. These factors may, however, result in biopersistence of fibres deposited in the respiratory tract.

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential

Additional information

Absorption:

Acute and sub-chronic inhalation studies and an acute oral toxicity showed no evidence of systemic toxicity. The effects seen in the inhalation studies were attributable to local effects in the lung and upper respiratory tract. Although the molecular weight does not preclude absorption, the substance has very low solubility in water and organic  solvents. In view of this low solubility and the toxicity study results, it is unlikely that any significant systemic absorption of this substance would occur, although transport of sufficently small fibres, by phagocytic cells, into the lymphatic circulation is a possibility.

Distribution, Metabolism,Excretion

Since it is unlikely that any significant absorption could occur, discussion of distribution, metabolism and excretion is largely irrelevant for this inorganic substance. Fibres entering the lymphatic system would be unlikely to dissolve and become bioavailable due to the very low solubility. These factors may, however, result in biopersistence of fibres deposited in the respiratory tract.

Categories Display