Benzotriazole

Endpoint summary

Link to relevant study record(s)

Reference

Endpoint:

basic toxicokinetics

Type of information:

other: toxicokinetic assessment

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: toxicokinetic assessment based on physicochemical data and available studies.

Objective of study:

toxicokinetics

Principles of method if other than guideline:

Assessment of the toxicokinetic behaviour of the substance to the extent that can be derived from the relevant available information, EC 1907/2006, Annex VII, 8.8.1

Metabolites identified:

yes

Details on metabolites:

5-hydroxybenzotriazole 1.6%
4-hydroxybenzotriazole 0.32%

Conclusions:

Interpretation of results (migrated information): low bioaccumulation potential based on study results
Based on the physicochemical data and the supporting study by Hoffmann the toxicokinetic properties of Benzotriazole are assesssed.

Executive summary:

Absorption: for the dermal and oral route, an absorption of 100% are assumed,

for the inhalative route no relevant absorption is estimated and 10% are assumed.

Distribution: no information

Metabolism and Excretion: metabolism rate is rather low (supporting study) and no Phase II reactions may occur.

Renale and fecal excretion are the prominent excretion routes.

Description of key information

To estimate the toxicokinetics properties of the substance, physicochemical parameters are

utilised (In accordance with Regulation (EC) 1907/2006, Annex VIII, 8.8.1)

Key value for chemical safety assessment

Bioaccumulation potential:

low bioaccumulation potential

Absorption rate - oral (%):

100

Absorption rate - dermal (%):

100

Absorption rate - inhalation (%):

10

Additional information

There is one study available on the metabolism of 1H-Benzotriazole. However, this study

does not give sufficient information for this endpoint and is regarded as supporting study.

A Report from the Dutch expert committee on occupational standards, dated 2000, does not lead to any conclusion.

(Health Council of the Netherlands: Dutch expert committee on occupational standards (DECOS), 1,2,3 -Benzotriazole, ISBN: 90-5549-348-1)

More actual literature is not avaible to our knowledge.

Physicochemical parameters used for toxicokinetic Endpoint summary:

Parameter	Value used for CSR
Molecular weight	119.14 g/mol
Melting point	99 °C
Boiling point	> 350 °C (at 1,1013 hPa)
Density	1.4 g/cm^3(at 15 °C)
Vapour pressure	0.01 kPa (at 20 °C)
Partition coefficient n-octanol/water (log POW)	1.44 (at 25 °C)
Water solubility	20 g/L (at 25 °C)
pH	4.7 (calculated for 20 g/L)
pKa	8.57 (at 25 °C)
Particle size	Typically 1256, range 800 - 2000 µm

Based on these parameters, the bioaccumulation potential is judged as low (log P_OW < 4)

The substance is a solid with a high boiling point and a low Vapour pressure, the particle size is large,

which leads to a low absorption rate by inhalation.

For dermal and oral Absorption rate 100 % are assumed by default.