Magnesium 2-ethylhexanoate

Endpoint summary

Description of key information

No skin sensitisation study with magnesium 2-ethylhexanoate is available, thus the skin sensitisation potential will be addressed with existing data on the assessment entities magnesium and 2‑ethylhexanoic acid.

Magnesium 2-ethylhexanoate is not expected to show signs of dermal sensitisation, since the two assessment entities magnesium and 2‑ethylhexanoic acid have not shown any skin sensitisation potential in in vivo experiments.

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Magnesium

Evaluation of the sensitisation potential of a substance was usually carried out in animal models. Nowadays, there is much interest in reducing and ultimately replacing current animal tests. The human cell line activation test (h-CLAT) and the ARE-Nrf2 luciferase test method were recently adopted as alternative methods for skin sensitization. Both test systems are based on human cell lines, such as the human monocytic leukaemia cells THP-1 and the KeratinoSens™ cells which are cultured either in RMPI-1640 medium or DMEM (OECD guideline No. 422D and 422E). Both media are supplemented with magnesium salts at concentrations ranging from 0.4 to 0.81 mM. These methods were validated and accepted under these conditions and demonstrate that in vitro cell culture systems are dependent on magnesium containing media.

 

Other commercial available and daily used cosmetic products (body cream or lotion) contain magnesium sulphate and magnesium stearate. The Cosmetic Ingredient Review (CIR) Expert Panel reviewed the safety of magnesium sulphate, which functions as a bulking agent in cosmetic products and is being used at concentrations up to 11 % and 25 % in leave-on and rinse-off products, respectively. The CIR Expert Panel noted that the history of safe medical use of magnesium sulphate indicates no significant toxicity concerns relating to systemic exposure to this ingredient. “The skin sensitization potential of anhydrous magnesium sulphate (in propylene glycol) was evaluated using the mouse local lymph node assay, according OECD Guideline 429. Three groups of 5 mice were used, and the dorsal surface of both ears was epidermally treated with the test substance (10 %, 25 %, and 50 %) at a dose volume of 25 μL/ear. A vehicle control group was also included in the study. The animals were then injected i.v. with3H-methyl thymidine, killed, and the draining auricular lymph node of each ear was excised. Lymph nodes were pooled for each animal, and cell suspensions prepared. The stimulation index (SI) was calculated for each group. The SI is defined as the ratio of the DPM/group compared to the DPM/vehicle control group. Because there was no indication that the test substance elicited an SI of ≥ 3 when tested up to a concentration of 50 %, anhydrous magnesium sulphate was considered a non-sensitizer” (Cosmetic Ingredient Review Expert Panel, 2014).

Magnesium stearate is widely used in cosmetic products because of its adhesive and waterproofing properties such as a dry binder in face powders. It was reported to be used in 167 preparations in 1976, with the highest concentration occurring in face powder up to 25 %. In 2001 the FDA summarized that magnesium stearate was used in 96 preparations with a concentration ranging from 0.02- 8 %. Magnesium stearate is insoluble in water and is also used as food supplement or for drug manufacturing. A safety assessment of magnesium stearate was published in 1982 with the conclusion that this substance “is safe as cosmetic ingredient in the present practices of use and concentration” (Elder 1982).

2-ethylhexanoic acid

In a guinea pig maximization assay (Berol Kemi AB, 1979), 0/10 female Dunkin-Hartley guinea pigs exhibited a response 48 h after induction and challenge with 5 % (w/w) and 2 % (w/w) aqueous 2‑ethylhexanoic acid solution, respectively. The intracutaneous injections were performed with 1 % (w/w) aqueous 2-ethylhexanoic acid solution. In summary, there is no evidence of a notable sensitization potential of 2-ethylhexanoic acid.

 

Magnesium 2-ethylhexanoate

Magnesium 2-ethylhexanoate is not expected to have a skin sensitising activity, since the two assessment entities magnesium and 2-ethylhexanoic acid have not shown any skin sensitisation potential in experimental testing. Further experimental testing is therefore not required. For further information on the toxicity of the individual moieties, please refer to the relevant sections in the IUCLID and CSR.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

As the two assessment entities of magnesium 2 -ethylhexanoate did not show sensitising properties, one may safely assume that magnesium 2 -ethylhexanoate will also show no sensitising activity. According to the criteria of REGULATION (EC) No 1272/2008 adaptions, magnesium 2-ethylhexanoate does not have to be classified and has no obligatory labelling requirement for skin sensitisation.