What ingredients should I avoid if I have sensitive skin?

First of all, let’s clarify what “sensitive skin” means. All skin types can experience irritation at one point – either from overusing a product, or a reaction to an ingredient. However, people with truly  sensitive have impaired skin barriers. That means ingredients that are not generally considered irritants can cause a reaction.
One simple test: press your fingers across your face with light to medium pressure. Does it turn red? And do most products you try, from face washes to makeup, cause stinging or redness?
If yes, your skin is sensitive, then it is wise to avoid some strong ingredients. Don’t rely on a product label like “hypoallergenic” or “organic/natural”. Read the label!
SULPHATES
People with sensitive skin usually have a compromised skin barrier and usually have dry skin. Sulphates are proven to strip the skin of its moisture. They act as surfactants or soap but are very drying for the skin.
Sulphates are usually found in foaming products like shampoos or cleansers. On labels, you’ll find them as sodium lauryl sulfate (SLS) and sodium laureth sulfate (SLES).
FRAGRANCE
Fragrance is one of the most common skin irritants. especially for people who have allergy-prone skin, acne, eczema or rosacea. The American Contact Dermatitis Society (ACDS) actually declared it the ‘Contact Allergen of the Year” in 2007.
The 8 most common triggers are actually synthetic fragrances that help recreate a particular scent. This includes cinnamic alcohol, cinnamic aldehyde, eugenol, geraniol, alpha amyl cinnamic alcohol, and hydroxycitronellal. These are often used to mimic the smell of rose, lily of the valley, violet, clove and musk.
A product that is “fragrance free” has no additional fragrances, but you may pick up the natural scents of the ingredients used (like plant extracts or shea and cocoa butters).  It is has less risk of irritating the skin because it doesn’t add extra chemicals.

PETROLEUM
Oils that are derived from petroleum (sometimes called petrochemicals or synthetic emollients) are sometimes used in moisturizers or anti-ageing products because they plump the skin to hide the appearance of wrinkles.
However, petroleum and mineral oils are “occlusive” ingredients. This means these form a film that prevents any air, water or even the beneficial ingredients in your other skincare products from being absorbed. It can also block pores.
Gentler facial oils, such as jojoba and almond oil can give the moisturizing and plumping effect without the risk for irritation and breakouts.
ALCOHOL
This is the first ingredient that anyone with sensitive skin should avoid. These are typically used in toners or makeup remover pads, because they help create a “quick dry” finish, but these can dry the skin and cause redness and stinging.
PRESERVATIVES
Watch out for preservatives like Methylisothiazolinone. Tests conducted by London’s St John’s Institute of Dermatology showed that it triggered allergic reactions in 10% of their patients with sensitive skin. Some products use very small amounts (0.01%) and may be safer to use. Methylisothiazolinone is sometimes labeled MIT, MI, Neolone 950 preservative, Or MicroCare MIT.
The American Academy of Dermatology has also flagged imidazolidinyl urea and Diazolidinyl urea as a primary cause of contact dermatitis.
COLORANTS
Synthetic colors may help make a skin product look pretty, but can irritate sensitive skin. Colors are usually labeled as FD&C or D&C, followed by a color and a number.  For example you will see “FD&C Red No. 6” or “D&C Green No. 6.”

CHEMICAL SUNSCREEN INGREDIENTS
There are two kinds of sunscreens. Physical sunscreens contain ingredients like titanium dioxide or zinc oxide that deflect or scatter UV rays. Chemical sunscreens contain compounds that change UV rays into heat then release that from the skin.
If you have sensitive skin, stick to a physical sunscreen.  Chemical sunscreens may contain ingredients that can irritation or stinging. Some of the most common irritants are benzphenones (oxybenzone, octocryele, and cinnamates).
Physical sunscreens can also deflects the heat, which is better for people who get redness and rosacea.

PROTECT AND STRENGTHEN SENSITIVE SKIN
Aside from looking for gentle, non-irritating ingredients, seek those that build the skin barrier function and fight inflammation. Sunscreen is also important: damaged skin will always be more prone to redness and dryness, and UV exposure will weaken your skin barrier even more.
This holds true even for people who don’t have sensitive skin, but are experiencing irritation or skin sensitivity because of a bad reaction to a product, change in climate, hormonal fluctuations, or even stress. Sometimes our skin just needs a little more attention and care than usual.