(3-methacrylamidopropyl)trimethylammonium chloride

Endpoint summary

Description of key information

Experimental toxicokinetic studies are not available for MAPTAC. 
The physicochemical properties of MAPTAC (log P = -2.58, high water solubility) and the molecular weight of 220.74 g/mol are suggestive of absorption from the gastro-intestinal tract. Dermal absorption is expected to be low. Inhalative absorption is not considered a relevant route of exposure due to the very low vapour pressure of the substance.
Based on physicochemical properties, no potential for bioaccumulation is to be expected.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

100

Absorption rate - dermal (%):

100

Additional information

Experimental toxicokinetic studies are not available for MAPTAC. Thus, the assessment of toxicokinetics is based on the physicochemical properties of the substance.

 

Absorption

Oral absorption

The physicochemical properties of MAPTAC (log P = -2.58, high water solubility) and the molecular weight of 220.74 g/mol are in a range suggestive of absorption from the gastro-intestinal tract subsequent to oral ingestion. Although it is generally anticipated that ionised substances do not readily diffuse across biological membranes, for chemical safety assessment an oral absorption rate of 100% is assumed as a worst case default value in the absence of other data.

 

Dermal absorption

Based on physicochemical properties (log P <0 and water solubility > 10 g/L) MAPTAC is likely to be too hydrophilic to cross the lipid rich environment of the stratum corneum. Thus, dermal uptake is expected to be low. However, no reliable data are available. Thus, for chemical safety assessment a dermal absorption rate of 100% is assumed as a worst case default value in the absence of other data.

 

Inhalative absorption

Due to the very low vapour pressure of MAPTAC (the estimated vapour pressure of MAPTAC is 2.52E-07 Pa at 25°C), exposure via inhalation is highly unlikely and thus not taken into account for chemical safety assessment.

 

Distribution

As a small molecule a wide distribution can be expected. No information on potential target organs is available. However, as an ionised molecule, the substance is thought to not readily diffuse across biological membranes.

 

Metabolism and excretion

It is very difficult to predict the metabolic changes a substance may undergo on the basis of physico-chemical information alone.

However, based on the structure, the substance is likely to undergo hydrolysis by amidases, which in general have a broad substrate specificity. Amidases are a group of non-specific enzymes that are widely distributed throughout the body and are known to show high activity within many tissues and organs. Hydrolysis of MAPTAC would result in Methacrylic acid and Aminocholine and finally Choline.

(CF READ-ACROSS DATA ON METHACRYLIC ACID AND METHYL METHACRYLATE).

Methacrylic acid is cleared rapidly from blood by standard physiological pathways, with the majority of the administered dose being exhaled as CO2.

Choline is a naturally occurring component which contributes to vital biological functions, e.g. the synthesis of phospholipids, which are structural cell components, as precursor for the intracellular messenger molecules, and for acetylcholine. Choline produced from MAPTAC-metabolism would be indistinguishable from Choline from other sources. Thus, further considerations on excretion are not necessary.

 

Bioaccumulation

Based on the low log P the substance is unlikely to accumulate with the repeated intermittent exposure patterns normally encountered in the workplace.