Registration Dossier

Administrative data

Link to relevant study record(s)

Description of key information

There were no studies available in which the toxicokinetic properties of TMPTMA were investigated. However, as per REACH guidance document R7.C (2014), information on absorption, distribution, metabolism and excretion may be deduced from the physicochemical properties. TMPTMA shows a low toxicity by oral and dermal route in the studies. Morever, based on a QSAR, no dermal absorption study is expected with TMPTMA.

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential
Absorption rate - oral (%):
100
Absorption rate - dermal (%):
10
Absorption rate - inhalation (%):
100

Additional information

TMPTMA is a substance having a molecular weight of ~338 g/mol. It is a liquid with a tested water solubility of 20 mg/L. Volatility was determined to be about 0.003 Pa at 20 and 50 °C and has a lipophilic character (log Pow slightly higher than 4). Hydrolysis calculation concluded the half-life of the substance at 25° C was 6.89 years at pH8 and 68.88 years at pH7. The surface tension is 53 mN/m. Detail information can be found in section 4 of TMPTMA IUCLID dossier.

There is no reliable and relevant information source in which the toxicokinetic properties (distribution, metabolism, elimination) of TMPTMA were investigated. The expected toxicokinetic behaviour is derived from the physicochemical properties and the results from the available toxicological/toxicokinetic publication following the guide given in the REACH guidance document 7c (2014):

Oral and GI absorption: The result of hydrolysis experiment shows relative stability at pH 7 and pH 9. It is not expected that substance is significantly hydrolysed in GI. Moreover, based on the water solubility the substance, its solubility in GI fluid is supposed to be limited. It can then be expected that the substance can only be partially absorbed in the gastrointestinal system, due to its molecular weight. Although no death and no symptom occurred in a limit acute oral toxicity study, this is expected to be due to the intrinsic low toxicity of the substance.

Inhalation absorption: It can be assumed that the TMPTMA will be effectively removed in the upper respiratory tract. Absorption is still possible via upper mucosa but limited by the inhaled amount which is assumed to be low due to the low vapour pressure.

Dermal absorption: Based on the physico-chemical information (TMPTMA has a molecular weight < 500 and is a lipophilic substance (log Pow > 4)), the dermal absorption is possible. However no signs of toxicity were observed in an acute dermal toxicity study and negative results were obtained with GPMT, both maybe due to the low toxicity of the substance. Moreover, the QSAR prediction indicates that TMPTMA is not absorbed by dermal route (0% of dermal absorption). For the risk evaluation, 10% of dermal absorption is used by default.

Distribution: The physico-chemical information (molecular weight, lipophilicity and water solubility) indicates that TMPTMA could be distributed to many tissues.

Accumulative potential: Based on the physico-chemical information (log Pow, structure not containing ionisable elements and water solubility), it is concluded that the potential for bioaccumulation is low as it is not proposed for classification as PBT substance.

Metabolism: No indication available.

Reactivity: Reactivity to nucleophilic molecules (e. g. thiol or amine groups of proteins) can be expected considering the ester and alpha, beta-unsaturated functions of TMPTMA.

Excretion: Based on the physico-chemical information (molecular weight of ~338 g/mol in average and water solubility), excretion via bile can be expected.