What Is Peg-35 Castor Oil?
Peg-35 Castor Oil is a plant-derived ingredient made by reacting natural castor oil with about 35 units of ethylene oxide. The base oil comes from the seeds of the castor plant, a crop long valued for its thick fatty oil that has been used in soaps and hair preparations for generations. Chemists began ethoxylating castor oil in the mid 1900s to improve its solubility in water, which opened the door for broader use in modern cosmetic formulas.
The manufacturing process starts with purified castor oil. Under controlled heat and pressure, ethylene oxide gas is introduced, attaching to the hydroxyl groups on the oil molecules. The result is a nonionic surfactant that balances water and oil phases with ease. Thanks to this dual nature, Peg-35 Castor Oil shows up in a wide range of products such as facial cleansers, makeup removers, micellar waters, shampoos, bath oils, sheet masks, lightweight moisturizers, anti-aging serums and exfoliating treatments.
Peg-35 Castor Oil’s Cosmetic Benefits/Uses
In formulas, Peg-35 Castor Oil pulls double duty, giving chemists reliable performance while keeping textures pleasant for the user.
- Cleansing: Its surfactant action loosens dirt, excess sebum and makeup, allowing them to rinse away with water. This gentle cleansing ability makes it popular in face washes and two-phase eye makeup removers where mildness is key.
- Emulsifying: The ingredient acts as a bridge between oil and water so creams stay smooth, lotions remain stable and clear gels do not separate. By holding everything together, it helps deliver an even spread of active ingredients across the skin or hair.
Who Can Use Peg-35 Castor Oil
Thanks to its gentle nature Peg-35 Castor Oil suits most skin types including dry, normal, combination and oily. Sensitive skin usually tolerates it well because it is nonionic and low foaming, though anyone with a known castor oil allergy should steer clear since the base oil is still present.
The ingredient is plant derived so it is suitable for vegans and vegetarians. No animal parts or by-products are used during manufacture.
Pregnant or breastfeeding women can generally use products containing Peg-35 Castor Oil as it is applied on the surface of the skin and not known to penetrate deeply. This is not medical advice. Expectant and nursing mothers should show any cosmetic formula they plan to use to their doctor to be extra safe.
Peg-35 Castor Oil does not increase the skin’s sensitivity to the sun so there is no special sunscreen warning beyond the usual daily protection.
It is also free of added fragrance and dyes so it rarely clashes with other skincare steps or active ingredients.
Potential Side Effects/Adverse Reactions
Side effects from topical Peg-35 Castor Oil vary from person to person. The points below outline potential issues yet most users will not run into them when the ingredient is formulated and used correctly.
- Mild skin redness or stinging if the user is allergic to castor oil
- Watery or irritated eyes when used in high amounts near the lash line
- Temporary dryness if the cleanser is left on the skin too long
- Rare clogged pores in very acne prone skin when formulas contain a high overall oil load
- Contact dermatitis in people with a confirmed sensitivity to polyethylene glycols
If you experience any negative reaction stop using the product and seek advice from a healthcare professional
Comedogenic Rating
Rating: 1/5
Peg-35 Castor Oil starts with castor oil, which on its own sits low on the comedogenic scale, then becomes even less pore clogging once it is ethoxylated. The added PEG chains make the molecule more water soluble so it rinses away easily without lingering in follicles. Formulas that use sensible oil levels rarely trigger blemishes in most people.
Because of this low rating, the ingredient is generally considered safe for acne prone or breakout prone skin, provided the rest of the formula is also lightweight.
Keep in mind that overall product design matters too. A rich balm packed with heavy butters can still clog pores even if Peg-35 Castor Oil itself is nearly non comedogenic.
Summary
Peg-35 Castor Oil serves two main roles: it lifts away grime as a mild cleanser and it stabilises mixtures as an emulsifier. The PEG side loves water while the castor side bonds with oils, letting it glide between both phases and keep textures uniform.
The ingredient is a quiet workhorse found in everything from micellar waters to gentle shampoos, yet it rarely makes marketing headlines. Chemists value its reliability, which is why it continues to appear in both legacy and new formulas.
Safety wise, it has a long record of topical use with low irritation risk. Most people can enjoy products that contain it, though anyone introducing a new skincare item should still do a small patch test first to make sure their skin agrees.