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Administrative data

Endpoint:
basic toxicokinetics
Type of information:
other: statement
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Based on Physical and Chemical properties

Data source

Reference
Reference Type:
other: statement
Title:
Toxicokinetics statement
Author:
Anonymous
Year:
2013

Materials and methods

Results and discussion

Toxicokinetic / pharmacokinetic studies

Details on absorption:
Oral / gastrointestinal absorption
With a low molecular weight (164.20 g/mol), high water solubility (1000 g/L) and log Kow of -0.69, oral/gastrointestinal absorption of TOU is favoured subsequent to oral ingestion. Log Kow values between -1 and 4 are favourable for absorption by passive diffusion.

Inhalation absorption
TOU is a substance with a medium volatility but may be available for inhalation as a vapour. Its moderate log Kow value is favourable for absorption directly across the respiratory tract epithelium by passive diffusion. High solubility of TOU in water indicates that it may be retained within the mucus.

Dermal absorption
As a liquid with a molecular weight close to 100 g/mol, TOU dermal uptake is favoured.
Based on molecular weight < 500 and log Kow in the (-1, 4) range, default dermal absorption of TOU is set to 100% for risk assessment.
Details on distribution in tissues:
A wide distribution is expected due to the low molecular weight. As a small water-soluble molecule, TOU is going to diffuse through aqueous channels and pores.
Details on excretion:
TOU is not considered as substance with a potential to accumulate within the body. The liver is known to be the greatest capacity for metabolism and the 28-day dermal study shows no significant increases in liver weights of male and female rats exposed to 1000 mg/kg bw/d of TOU.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information): no bioaccumulation potential based on study results
The following values for absorption assessment were taken into account according to TOU behaviour (absorption, metabolism, distribution and elimination):
oral absorption of TOU is set to 100% for risk assessment;
inhalation absorption of TOU is set to 100% for risk assessment;
dermal absorption of TOU is set to 100% for risk assessment.

At more, no bioaccumulation potentiel is expected due to the low log Kow value of the test item.
Executive summary:

ABSORPTION

Oral / gastrointestinal absorption

With a low molecular weight (164.20 g/mol), high water solubility (1000 g/L) and log Kow of -0.69, oral/gastrointestinal absorption of TOU is favoured subsequent to oral ingestion. Log Kow values between -1 and 4 are favourable for absorption by passive diffusion.

Oral absorption of TOU is set to 100% for risk assessment

Inhalation absorption

TOU is a substance with a medium volatility but may be available for inhalation as a vapour. Its moderate log Kow value is favourable for absorption directly across the respiratory tract epithelium by passive diffusion. High solubility of TOU in water indicates that it may be retained within the mucus.

Inhalation absorption of TOU is set to 100% for risk assessment

 

Dermal absorption

As a liquid with a molecular weight close to 100 g/mol, TOU dermal uptake is favoured.

Based on molecular weight < 500 and log Kow in the (-1, 4) range, default dermal absorption of TOU is set to 100% for risk assessment.

Dermal absorption of TOU is set to 100% for risk assessment

 

DISTRIBUTION

A wide distribution is expected due to the low molecular weight. As a small water-soluble molecule, TOU is going to diffuse through aqueous channels and pores.  

METABOLISM and EXCRETION

 

TOU is not considered as substance with a potential to accumulate within the body. The liver is known to be the greatest capacity for metabolism and the 28-day dermal study shows no significant increases in liver weights of male and female rats exposed to 1000 mg/kg bw/d of TOU. 

 

The following values for absorption assessment were taken into account according to TOU behaviour (absorption, metabolism, distribution and elimination):

oral absorption of TOU is set to 100% for risk assessment;

inhalation absorption of TOU is set to 100% for risk assessment;

dermal absorption of TOU is set to 100% for risk assessment.

At more, no bioaccumulation potentiel is expected due to the low log Kow value of the test item.

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