Octadecanoic acid, reaction products with diethylenetriamine and urea, acetates

Endpoint summary

Link to relevant study record(s)

Reference

Endpoint:

basic toxicokinetics

Type of information:

other: Expert assessment

Adequacy of study:

key study

Study period:

2015

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Expert assessment

Guideline:

other: Expert assessment

GLP compliance:

no

Specific details on test material used for the study:

Substance name: Octadecanoic acid, reaction products with diethylenetriamine and urea, acetates
Code name: FAT 93580A
CAS No.: 84962-05-0
EC No.: 284-698-4
Structure: UVCB
Physico-chemical properties:
Appearance/colour: White-yellowish waxy solid
Molecular weight: 367.3 – 645.6 g/mol
Vapour pressure: 2.6 mPa at 25 °C

Conclusions:

FAT 93580A-pellet (CAS no. 84962-05-0) of 94.3 % is a multi-constituent substance composed of 10 chemical entities with concentration range from 0.78 to 25.73 %. They are the following derivatives: imidazol with palmitamide and stearamide, 2-oxoimidazolidine with palmitamide and stearamide, dipalmitamide, distearamide, palmitamide and stearamide acetate (as non derivative) No detailed data on absorption, distribution, metabolism and excretion (ADME) for FAT 93580A-pellet is available. The compounds of this multi-constituent substance except acetate (MW: 59.04 g/mol, which metabolism enters in the citric acid cycle), all have moderate and high molecular weights ranging from 367.3 g/mol (N-(2-(2- oxoimidazolidin-1-yl)ethyl)palmitamide) to 645.6 g/mol (N-(2-(2-nonadecyl-4,5-dihydro-1H-imidazol-1-yl)ethyl) stearamide). I.e. the molecular weight of the majority constituents are > 500 g/mol. This multi-constituent substance is a waxy solid, therefore is considered as non-volatile substance and inhalation exposure of gases and particles is very unlikely. Due to the detergent-like nature of most ingredients a dermal uptake to some minor extent can not be excluded but due to the cationic charge the rate of uptake is assumed to be rather low. No systemic toxicity was observed in combined repeated dose toxicity study with the reproduction/developmental toxicity screening test in the Han Wistar rat when administered via oral (gavage) up to 1000 mg/kg bw/day FAT 93580A (the highest administered dose) (Pal-Kutas, 2013). It is in line with the literature data, where domestic detergents are described as materials having low systemic toxicity (Reichl FX, 2002). No local toxicity was observed in Episkin tests for skin corrosion and for skin irritation as well as in REET test for eye irritation (Warren, 2013; Sanders, 2013). The LLNA test showed negative response for FAT 93580A skin sensitisation (Henzell, 2013).

Executive summary:

Absorption:

No physical properties are available for individual substances of FAT 93580A.

The individual substances are composed from nonpolar and polar parts like long aliphatic chains for nonpolar part and peptide groups, imidazol and 2- oxoimidazolidine as polar part of molecules. Since almost of all molecules of multi-constituent substance have a high molecular weight, the oral and dermal absorption may be restricted. However, N-(2-(2-oxoimidazolidin-1-yl) ethyl)palmitamide, derived of palmitamide and 2-oxoimidazolidine as well as N-(2-(2-oxoimidazolidin-1-yl)ethyl)stearamide, derived of stearamide and 2- oxoimidazolidine at physiological pH range are non-ionic (determined by MarvinSketch) detergent-like substances which could be extensively absorbed by oral route (Reichl FX, 2002). All other remaining substances of FAT 93580A at physiological pH range are cationic (determined by MarvinSketch) detergent-like substances which could be marginally absorbed in gastrointestinal tract (Reichl FX, 2002). However, the oral absorption of such substances could be enhanced if they undergo micellular solubilisation by bile salts. Again, oral absorption of molecules similar to surfactants may be enhanced because of damage to cell membranes.

Distribution:

Since non-ionic substances (2-oxoimidazolidine derivatives) are supposed to diffuse readily across membranes, they will distribute throughout the body. In the LLNA study no positive result for the skin sensitisation was observed (Henzell, 2013), therefore plasma protein binding could be excluded. For cationic substances the available information does not allow to make a judgement about the potential distribution of the parent compounds.

Metabolism:

The secondary amines (having NH groups) of FAT 93580A molecules could undergo CYP450 hydroxylation following glucuronidation or sulphatation and producing more hydrophilic compounds. On the other hand, acting by amidases the substances of FAT 93580A could be cleaved to carboxylic acids and amino compounds (diethylenetriamine, etc.). Carboxylic acids will undergo complete metabolism via the fatty acid β-oxidation pathway.β-oxidation of fatty acids produces acetyl coenzyme A as a result of sequential removal of two-carbon units from carboxylic acids. Acetyl coenzyme A is utilised for energy via the citric acid cycle or converted to acetoacetate and subsequently to other ketone bodies (EFSA 2008). Dietylenetriamine could be found unchanged in urine, suggesting that this compound is not extensively metabolised (Leung, 1997).

Elimination:

The oxidised and conjugated molecules of FAT 93580A could be eliminated preferentially by the faeces since glomerular filtration could be encumbered by the large molecular weight. Since the FAT 93580A substances have expressed polarity and high molecular weight they are less likely to undergo enterohepatic recycling. The parent non-absorbed compounds may be excreted in the faeces directly from gastrointestinal tract. The metabolised FAT 93580A to carboxylic acids by amidases could be eliminated by the citric acid cycle pathway, whereas diethylenetriamine may be eliminated unchanged in urine.

Description of key information

The uptake of the test substance via dermal route is very unlikely and since the substance is not classified for acute dermal, inhalation, and oral toxicity. The available information suggests that absorption of the test substance will primarily take place in the gastrointestinal tract following oral ingestion. Some absorption may also take place via damaged skin. Once absorbed, the substance would be distributed in the serum and in all likelihood excreted via the urine and faeces.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Additional information

Since no toxicokinetics studies are available for the test substance the following assessment is based on the available physiochemical properties and the results from other toxicological studies. FAT 93580A-pellet (CAS no. 84962-05-0) of 94.3 % is a multi-constituent substance composed of 10 chemical entities with concentration range from 0.78 to 25.73 %. They are the following derivatives: imidazol with palmitamide and stearamide, 2-oxoimidazolidine with palmitamide and stearamide, dipalmitamide, distearamide, palmitamide and stearamide acetate (as non derivative) No detailed data on absorption, distribution, metabolism and excretion (ADME) for FAT 93580A-pellet is available. The compounds of this multi-constituent substance except acetate (MW: 59.04 g/mol, which metabolism enters in the citric acid cycle), all have moderate and high molecular weights ranging from 367.3 g/mol (N-(2-(2- oxoimidazolidin-1-yl)ethyl)palmitamide) to 645.6 g/mol (N-(2-(2-nonadecyl-4,5-dihydro-1H-imidazol-1-yl)ethyl) stearamide). I.e. the molecular weight of the majority constituents are > 500 g/mol. This multi-constituent substance is a waxy solid, therefore is considered as non-volatile substance and inhalation exposure of gases and particles is very unlikely. Due to the detergent-like nature of most ingredients a dermal uptake to some minor extent can not be excluded but due to the cationic charge the rate of uptake is assumed to be rather low. No systemic toxicity was observed in combined repeated dose toxicity study with the reproduction/developmental toxicity screening test in the Han Wistar rat when administered via oral (gavage) up to 1000 mg/kg bw/day FAT 93580A (the highest administered dose) (Pal-Kutas, 2013). It is in line with the literature data, where domestic detergents are described as materials having low systemic toxicity (Reichl FX, 2002). No local toxicity was observed in Episkin tests for skin corrosion and for skin irritation as well as in REET test for eye irritation (Warren, 2013; Sanders, 2013). The LLNA test showed negative response for FAT 93580A skin sensitisation (Henzell, 2013).