Registration Dossier

Administrative data

Endpoint:
basic toxicokinetics, other
Type of information:
other: Qualitative judgement on the toxicokinetic behaviour based on physico-chemical characteristics
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Materials and methods

Objective of study:
toxicokinetics
Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
This qualitative judgement on the toxicokinetic behaviour based on physico-chemical characteristics follows the recommendations of ECHA (ECHA Endpoint specific guidance, Chapter R.7c; Section R.7.12.2.1)
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Details on test material:
Name of test material: Trimethylolpropanepoly(oxypropylene)triamine
EC no.: 500-105-6
CAS no.: 39423-51-3
Physical state: clear colourless liquid
Radiolabelling:
no

Results and discussion

Toxicokinetic / pharmacokinetic studies

Details on absorption:
Oral absorption:
Following the pKa of the substance (pKa = 10.25), the predominant form in biological system will be the undissociated form. Since the substance is a liquid, relatively small (MW = 440) and highly water soluble (562 g/L), it is expected to readily dissolve into gastrointestinal fluids. As the Log Kow is -1.13, passive diffusion might occur. Therefore, an oral absorption between 50% and 100% is expected.

Respiratory absorption:
As the substance is liquid at room temperature, with a high boiling point (> 235°C) and a low vapour pressure (0.0023 Pa at 20°C), no or only a limited number of airborne particles are expected. The substance is highly water soluble. As a consequence, the substance will be readily soluble in blood and a high amount of the substance will be absorbed per breath. Hydrophilic substances are effectively removed from the air in the upper respiratory tract. Since the substance has a moderate Log Kow value (-1.13) absorption might occur. As a worst case estimation: a 100% respiratory absorption is proposed.

Dermal absorption:
The substance is very hydrophilic (water solubility = 562000 mg/L and Log Pow =-1.13). Therefore it is expected that the penetration into the stratum corneum and hence dermal absorption will be limited. The substance has weak surface active properties, which might enhance dermal absorption slightly. It is generally accepted that dermal absorption will not be higher than oral absorption. As a default of 100% skin absorption is suggested for substances with a molecular weight below 500, the dermal absorption factor is set at 50 -100 % as for oral absorption.
Details on distribution in tissues:
Wide distribution throughout the body is to be expected as the substance is a relatively small, highly watersoluble molecule. It will diffuse through aqueous channels and pores. Due to its hydrophilic behaviour, uptake into cells might be limited.
Details on excretion:
Excretion via urine is expected, as the substance is highly water soluble and has a relatively small MW. However, ionisation at the pH of urine will be very limited as pKa is 10.25.

Metabolite characterisation studies

Metabolites identified:
not specified
Details on metabolites:
not specified

Applicant's summary and conclusion

Conclusions:
A qualitative assessment on the toxicokinetic behaviour was performed on the basis of physico-chemical characteristics.
The substance is relatively small (MW = 440), very water soluble, and hydrophilic. The substance has weak surface active properties and causes mild irritation to skin and serious eye damage.
An absorption factor of 100% is proposed for inhalation and 50-100% for oral and dermal absorption.