Fatty acids, C16-18, barium salts

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Information was taken from several review documents published by national and international agencies on human health aspects of fatty acids in human nutrition, cosmetics and household cleaning products. This information represents the highest level of reliability and acceptance.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Final report on the safety assessment of oleic acid, lauric acid, palmitic acid, myristic acid and stearic acid

Author:

Cosmetic Ingredient Review

Year:

1987

Bibliographic source:

Journal of the American College of Toxicology, Volume 6, Numer 3

Reference 2

Reference Type:

publication

Title:

Human & Environmental Risk Assessment on ingredients of European household cleaning products, Fatty Acid Salts, Human Health Risk Assessment

Author:

HERA

Year:

2002

Bibliographic source:

http://www.heraproject.com/files/5-HH-04-HERA%20Fatty%20acid%20salts%20HH%20web%20wd.pdf

Reference 3

Reference Type:

publication

Title:

Toxicological evaluation of some food colours, emulsifiers, stabilizers, anti-cracking agents and certain others substances

Author:

World Health Organization (WHO)

Year:

1974

Bibliographic source:

WHO Food Additive Series No. 5

Reference 4

Reference Type:

publication

Title:

WHO FOOD ADDITIVES SERIES: 42, linear and branched-chain aliphatic, unsaturated, unconjugated alcohols, aldehydes, acids and related esters

Author:

World Health Organization (WHO)

Year:

1999

Bibliographic source:

http://www.inchem.org/documents/jecfa/jecmono/v042je16.htm

Materials and methods

Objective of study:

absorption

excretion

Principles of method if other than guideline:

Review documents on human health aspects of ingredients in human nutrition, cosmetic products and household cleaning products. Information contained therein were collected and reviewed by national and international expert panels.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Fatty acids, C16-C18

IUPAC Name:

Fatty acids, C16-C18

Constituent 2

Reference substance name:

Stearic acid

EC Number:

200-313-4

EC Name:

Stearic acid

Cas Number:

57-11-4

IUPAC Name:

stearic acid

Test material form:

other: via diet, cosmetics, household cleaning products

Test animals

Species:

human

Sex:

male/female

Administration / exposure

Route of administration:

other: oral, dermal

Details on exposure:

dietary intake, dermal application as cosmetics or dermal contact as household cleaning product

Duration and frequency of treatment / exposure:

daily

Results and discussion

Main ADME results

Main ADME results 1

Type:

absorption

Results:

> 90% (av. 96-98% in healthy adult) via passive or facilitated diffusion

Main ADME results 2

Type:

distribution

Results:

absorbed as micelle aggregates, esterified with glycerol in chylomicrons and very low density lipoproteins, and transported via the lymphatic system

Main ADME results 3

Type:

excretion

Results:

via faeces <2%

Toxicokinetic / pharmacokinetic studies

Details on absorption:

Fatty acids are an endogenous part of every living cell and are an essential dietary requirement. Proposed mechanisms for fatty acid uptake by different tissues range from passive diffusion to facilitated diffusion or a combination of both (Abumrad et al. 1984; Harris et al., 1980).

Details on distribution in tissues:

Fatty acids taken up by the tissues can either be stored in the form of triglycerides (98% of which occurs in adipose tissue depots) or they can be oxidised for energy via the β-oxidation and tricarboxylic acid cycle pathways of catabolism (normal fatty acid metabolism).

Metabolite characterisation studies

Details on metabolites:

Fatty acids, C16-C18 can be divided in three steps (1) activation and transport into the mitochondria (2) beta-oxidation and (3) electron transport chain. The fatty acid is completely oxidised in a process in which two carbon molecules acetyl-CoA are repeatedly cleaved from the fatty acid. The resulting Acetyl-CoA can enter the citric acid cycle. After the beta-oxidation no further metabolites are present.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): other: bioaccumulation potential is not relevant since fatty acids C16-C18 are part of the typical European diet
Fatty acids C16-C18 is almost completely absorbed as micelle aggregates in the GI tract of humans and occurs via passive or facilitated diffusion. The chylomicrons and low-density lipid proteins are transported via the lymphatic system. The resulting linear fatty acids participate in normal fatty acid metabolism. During beta-oxidation in the fatty acid is completely oxidised resulting in Acetyl-CoA, no metabolites or residues are formed.