Many studies have been conducted on PEG-60 Hydrogenated castor oil to verify its dermatological safety. It has been shown to be generally non-irritating and non-sensitizing to human skin in concentrations up to 100% (1).

References____________________________________

(1) Jang HJ, Shin CY, Kim KB. Safety Evaluation of Polyethylene Glycol (PEG) Compounds for Cosmetic Use. Toxicol Res. 2015 Jun;31(2):105-36. doi: 10.5487/TR.2015.31.2.105. 

Compendium of the most significant studies with reference to properties, intake, effects.

Final report on the safety assessment of Ricinus Communis (Castor) Seed Oil, Hydrogenated Castor Oil, Glyceryl Ricinoleate, Glyceryl Ricinoleate SE, Ricinoleic Acid, Potassium Ricinoleate, Sodium Ricinoleate, Zinc Ricinoleate, Cetyl Ricinoleate, Ethyl Ricinoleate, Glycol Ricinoleate, Isopropyl Ricinoleate, Methyl Ricinoleate, and Octyldodecyl Ricinoleate. Int J Toxicol. 2007;26 Suppl 3:31-77. doi: 10.1080/10915810701663150.

Shaw DW. Allergic contact dermatitis from 12-hydroxystearic Acid and hydrogenated castor oil. Dermatitis. 2009 Nov-Dec;20(6):E16-20.

Yhirayha C, Soontaranon S, Wittaya-Areekul S, Pitaksuteepong T. Formulation of lyotropic liquid crystal containing mulberry stem extract: influences of formulation ingredients on the formation and the nanostructure. Int J Cosmet Sci. 2014 Jun;36(3):213-20. doi: 10.1111/ics.12116.

Müller HD, Eick S, Moritz A, Lussi A, Gruber R. Cytotoxicity and Antimicrobial Activity of Oral Rinses In Vitro. Biomed Res Int. 2017;2017:4019723. doi: 10.1155/2017/4019723.

Fiala S, Roman M, Inacio R, Mashal S, Brown MB, Jones SA. New insights into eutectic cream skin penetration enhancement. Int J Pharm. 2016 Feb 29;499(1-2):403-411. doi: 10.1016/j.ijpharm.2015.12.059.

Fujii MY, Asakawa Y, Fukami T. Potential application of novel liquid crystal nanoparticles of isostearyl glyceryl ether for transdermal delivery of 4-biphenyl acetic acid. Int J Pharm. 2020 Feb 15;575:118935. doi: 10.1016/j.ijpharm.2019.118935.