LUSH Lip Scrub

The ranges of the fatty acids differ so much because it varies batch to batch depending on the cultivar and the growing conditions.

In skincare, it mostly does good plant oil stuff: it softens, sits on the surface to slow water evaporation, and makes formulas feel richer.

Now the honest part. Corn oil isn't studied much in dermatology but we do know it's the go-to vehicle in lab research. So there's decades of research where corn oil was the boring control; it never produced an effect of its own but we also don't have much research on it doing something exciting for your skin.

The one thing worth talking about is linoleic. Acne-prone follicles tend to be low in linoleate and a small study found topical linoleic acid shrank microcomedones by around 25% over a month. That was pure linoleic acid and not corn oil so it should be filed under "promising theory" rather than "proven benefit".

Concentration use can be anywhere from trace amounts to about 14% (the high end shows up in cleansers, moisturizers, body creams, and masks). Corn germ oil, which is basically the same ingredient under a different INCI name, has been reported as high as 25% but most of the time you're looking at low single digits.

Corn oil itself isn't a common allergen. Allergies to actual corn are triggered by corn proteins which is mostly refined out of the oil for cosmetic use. How much of the protein removed depends on the manufacturing process, so it's always better to patch test just in case.

This ingredient does have a comedogenic rating of 0-3, but this doesn't mean a formula with this ingredient will clog pores.

Human testing has proved that any finished product with this ingredient won't automatically make you break out; it really comes down to concentration, formula, and your skin.

The Malassezia yeast can't make its own fatty acids and breaks down oils around it to feed. Lab research shows the yeast grows when fatty acids in the C11-C24 range are available. Since corn oil is almost entirely C16-C18 fatty acids, this ingredient may not be fungal acne safe.

Other major parts of Rose Oil include citronellol and geraniol. Both of these are known EU allergens and cause contact-allergies.

The downsides of this ingredient outweight the positives.

Solvents are used to keep ingredients together in a product. They can help dissolve ingredients to stable bases or help evenly distribute ingredients throughout the product.

Due to its fragrance, Benzyl Benzoate can be sensitizing and may cause contact dermatitis. It is a known EU allergen. We recommend speaking with a professional if you have any concerns.

Benzyl Benzoate can be naturally found in cranberries and peaches.

You should know this ingredient is a known EU fragrance allergen.

Animal studies classifies this ingredient as a weak-to-moderate skin sensitizer and clinical patch testing on eczema patients confirmed it to be both a contact allergen and irritant.

The term 'citral' is a collective term for two geometric isomers: geranial/Citral A and neral/Citral B.

The term 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term. For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance.

Citronellol is a modified terpene. Terpenes are unsaturated hydrocarbons found in plants. They make up the primary part of essential oils.

Citronellol is not able to be absorbed into deeper layers of the skin. It has low permeability,

Citronellol is also a natural insect repellent.

There's some lab work behind its reputation; in one study, it acted as an antioxidant and calmed inflammation in human immune cells. But it also killed skin cells (keratinocytes) in a dish.

It stopped damaging those cells and still reduced swelling in mice when the researchers wrapped it in tiny capsules to slow its release.

One study that is quoted out of context frequently: clove oil killed human skin and blood vessel cells at levels as low as 0.03%, and about 73% of that came down to eugenol. Keep in mind those were bare cells sitting in a dish with no skin barrier in the way (which is a lot harsher than what happens on your actual face).

On concentrations, it is restricted to 0.64% in leave-on products + body products, 0.21% in baby + lip products, 2.5% in fine fragrance and 4.9% in rinse-off. Real formulas usually land far below those caps.

Allergy is the actual story with this ingredient. It is one of the eight markers dermatologists use for allergy testing, and the EU requires it to be named on the label above 0.001% in leave-on and 0.01% in rinse-off products.

It is also a prohapten, meaning it needs enzymatic activation in skin to become allergenic, so sensitivity varies between people.

Rates are modest but not trivial: in a classic EECDRG multicentre study, 13 of about 1,300 patch-tested patients reacted to eugenol, and in eugenol-allergic subjects the lowest positive patch test concentration was 0.031%, with 56% reacting in a 21-day repeated open application test at 0.5% to 2.7%.

Normal use levels are generally fine if you are not already sensitized.

This ingredient is hydrophobic, meaning it is not soluble in water.

Geraniol can be found in many essential oils including Rose Oil and Citronella Oil. The scent of Geraniol is often described as "rose-like". Many foods also contain Geraniol for fruit flavoring.

Geraniol can irritate the skin when exposed to air. However, irritation depends on the ability of geraniol to penetrate into the skin. In general, geraniol is not able to penetrate skin easily.

Geraniol is colorless and has low water-solubility. However, it is soluble in common organic solvents.

Like citronellol, it is a natural insect repellent.

2,6-Octadien-1-ol, 3,7-dimethyl-, (2E)-

You'll typically see this ingredient used in very small amounts; anything above 0.001% in a leave-on product or 0.01% in a rinse-off has to be named on the label in the EU. The citrus oils that carry it sit around 0.5-1% in a finished formula.

Fresh limonene is a weak allergen; the real issue is that it slowly reacts with air and then breaks down from oxidation to create hydroperoxides (which are strong sensitizers). This is why suppliers are required to keep the peroxide value below 20 mmol.

Positive reactions in people being investigated for eczema vary:

It's worth skipping if you have a known fragrance allergy or a compromised barrier, but the risk is low for most people.

Older or long-opened products are also more likely to bother you than fresh ones due to oxidation.

The EU requires it to be named on the label above 0.001% in leave-on and 0.01% in rinse-off products.

Fresh linalool is a weak sensitizer but air exposure turns some of it into hydroperoxides, which are strong sensitizers. Those oxidation products are the actual allergy concern.

Patch-test clinics see positive reactions to linalool hydroperoxides in about 4% to 12% of dermatitis patients depending on country and test concentration.

Resassuringly, one analytical study found hydroperoxide levels in real fragranced products to be orders of magnitude below what induced sensitization in animal studies with no evidence of oxidation building up during normal storage.

The practical takeaway is that linalool is fine for most people but worth avoiding if you have a confirmed fragrance contact allergy or a badly compromised barrier.

Products stored a long time after opening are also the high-risk scenario since that is when oxidation happens.

The scent of linalool is described as floral, spicy tropical, and citrus-like.

Here is the official definition from the The International Cosmetic Ingredient Dictionary and Handbook:

“Aroma is a term for ingredient labeling used to identify that a product contains a material or combination of materials normally added to a cosmetic to produce or to mask a particular flavor.”

INCI shows the only purpose of aroma to be "flavouring".

However, due to regulation differences, some companies may use aroma in place of parfum.

In Canada, this ingredient only has to be listed in concentrations above 1%.