Skin Care Ingredients to Avoid
" As the largest organ of the body, the skin performs multiple critical functions, such as serving as the primary barrier to the external environment. For this reason, the skin is often exposed to potentially hazardous agents, including chemicals, which may contribute to the onset of a spectrum of adverse health effects ranging from localized damage (e.g., irritant contact dermatitis and corrosion) to induction of immune-mediated responses (e.g., allergic contact dermatitis and pulmonary responses), or systemic toxicity (e.g., neurotoxicity and hepatoxicity). Understanding the hazards related to skin contact with chemicals is a critical component of modern occupational safety and health programs. "
Our skin is a wonderfully important organ, crucial to our survival (we wouldn't last long without it), and our overall health. Just as we want to take good care of our insides, we also want to take good care of our outside.
In an attempt to take care of our skin we slather it with beauty products, usually with the assumption that the product is doing something good or beneficial for our overall health or appearance, but sometimes these products have less than desirable ingredients - ingredients that we maybe should avoid, for various reasons (either they can cause irritation, skin damage, or they may pose health risks). Contact, inhalation, absorption; there are various ways that the ingredients we use on the outside of our bodies can affect our health, both externally and internally, not to mention can contribute to the damage of our skin.
But why would we want to avoid certain ingredients for health reasons, anyway? Doesn't our skin effectively keep out these "bad" chemicals?
Some suggest that our skin is such an effective barrier that virtually nothing can penetrate it, while others suggest that virtually everything penetrates the skin and enters into the bloodstream and therefore we need to use only "good", "natural" things on our skin.
The truth is somewhere in the middle.
After all, we know that transdermal drug delivery is a thing. Why would doctors have drugs be delivered through the skin if it wasn't an effective mode of delivery for certain chemicals? In fact, it has made an important medical contribution, although it has yet to meet its potential as an alternative therapy.
The skin consists of several layers. The outer layer of the epidermis, the stratum corneum, is lipophilic (oil-loving) and hydrophobic (water-hating). Oils penetrate into this top layer and generally don’t make it past that. The layers deeper down in the epidermis start to change in chemical composition and contain more water, making it harder for oil to penetrate further into the skin because oil and water do not mix. Instead, oil traps water beneath it and prevents the loss of water through evaporation (TEWL) thereby making your skin feel softer, smoother, and more hydrated.
Many skin care products are a blend of oil and water, which can penetrate the skin layers much more effectively. This is how we are able to deliver compounds to the deeper layers of the skin. If a product is ‘amphiphilic’ it can make it deeper into the layers of the skin (Förster, et. al, 2009) although this really does depend on the chemical in question and how it reacts with its ‘vehicle’ and the skin (Cal, 2006).
However, this still doesn’t mean that your lotions, creams and serums are being absorbed into your bloodstream. Absorption still depends on molecule size, chemical solubility, the ‘vehicle’ in which it is transported, and whether or not the chemical reacts with the enzymes in your skin. Some chemicals will simply never get that far in the first place because their molecules are too big and they can’t pass into the skin. Other chemicals are retained on the skin’s surface because they bind with other chemicals or even bind with the skin itself. However, for those that do make it into the skin, they may encounter enzymes that can break down or inactivate toxic chemicals. For some chemicals, such as some of the phthalic acid esters, the enzyme activity is so efficient that the chemical is completely metabolised during skin absorption (Hotchkiss, 1994). However, there are also enzymes in skin that may activate chemicals or make them more toxic. For example, scientists have established that hydrocarbons are harmless, but specific enzymes in the skin convert them into reactive compounds that can damage cellular DNA. We also now know that enzymes in the skin can activate and inactivate many drugs and foreign compounds, as well as the body’s own natural chemicals such as hormones, steroids and inflammatory mediators. The activities of these skin enzymes, however, may vary greatly between individuals and with age (Hotchkiss, 1994). In other words, our skin can protect us from exposure to certain chemicals while actually intensifying the effects of others.
Not to mention, all of us have different skin types based on our age, skin colour and environment. Even seasons and certain activities can affect the ability of our skin to deal with different chemicals. For instance, having a massage with lots of essential oils may increase their penetration into the skin, as the massage action increases blood flow to certain areas of the body.
People with skin disorders like dermatitis or very dry and damaged skin may also be sensitive to certain chemicals penetrating deeper into the layers of their skin. Their skin’s barrier properties can be compromised which means that the defences normally inherent in our skin are not functioning as normal. Absorption rates on our face and scalp are already 5-10x higher than on other parts of our body (Hotchkiss, 1994).
Furthermore, certain chemical compounds actually remain in the skin and act as a reservoir, being released at a later time. The design of particular medicines takes this into account – for example, salicylic acid was found to be excreted in urine more slowly when applied on the skin than when injected (WHO, 2006).
It’s clear that there are ways and means for certain chemicals to make it all the way into our bloodstream. Our skin is not an impermeable sheet of plastic. Stuff can get in and makes it down into the bottom layer of the skin where the blood vessels are. Luckily even then the body has defence mechanisms which can kick into action, depending on what’s entered your body in the first place. That doesn’t mean that all chemicals are neutralized though and some will undoubtedly make it into your bloodstream.
Our body’s largest organ protects us from the daily onslaught and can stop certain chemicals from getting into our bodies. On the other hand, while our skin isn’t a sponge, it’s certainly taking in some ingredients that we apply to our bodies and transporting them further down into the body where they may or may not make it into the bloodstream. But one thing is absolutely clear: it is impossible to put a figure on this absorption rate and it is impossible to estimate how much ends up in our bloodstream. Every person is different and every chemical is different. It is always good to question what you put on your skin but your body’s response will be individual. My advice to you? Read your labels, understand what you’re putting on your skin and consider a gentler alternative if you want or need one. There’s nothing wrong with being cautious.
Plus, many ingredients aren't necessarily "dangerous" in that they are not at risk of entering the blood stream, but may be dangerous to inhale, or to apply to the skin for other reasons such as irritation.
Here are some common ingredients in skin care that you may want to avoid.
Your skin care products shouldn’t have a drying effect on the skin, so a high alcohol content in them is a no-no. Alcohol in high concentrations strips the skin of its natural oils and leads to a loss of water in the skin’s upper layer. This means that the skin becomes dehydrated and might start to show fine lines easier, as well as develop cracks which allow other undesirable products and bacteria to penetrate more easily (beneficial in some instances, as we will see next), not to mention increase trans epidermal water loss.
However, antioxidants in small amounts of alcohol (lower on the list of ingredients) allows for these beneficial ingredients to penetrate the skin better (12). Alcohol creates temporary microscopic openings in the lipid bilayer that later close, leaving skin intact and healthy.
While anything with a high content of alcohol (anything especially in the first few ingredients) is going to be drying and damaging, when it is a part of a well-formulated skin care product, it can be a benefit by thinning out the solution, increasing its penetration into the skin, and ultimately, its efficacy.
But alcohol-containing skin care products do not cause the death of skin cells, the destruction of important aspects of skin, or the widespread systemic induction of free radicals, as some popular bloggers would have you believe. So, avoid it if you wish, and especially if you have dry or damaged skin, but keep in mind that it isn't a concern in low concentrations.
Look for: ALCOHOL; ETHANOL; ETHYL ALCOHOL (within the first few ingredients). Quick lesson: In chemistry, the suffix “-ol” is an indication a substance is an alcohol. There are a few exceptions, like panthenol, but “-ol” on the end is the general rule.
Triclosan has broad-spectrum anti-microbial activity against most gram-negative and gram-positive bacteria. It is widely used in personal care products, household items, medical devices, and clinical settings. Due to its extensive use, there is potential for humans in all age groups to receive life-time exposures to triclosan, and, indeed, triclosan has been detected in human tissues and the environment. It is often found as contaminants in people due to widespread use of antimicrobial cleaning products, and overuse may promote the development of bacterial resistance. Data gaps exist regarding the chronic dermal toxicity and carcinogenicity of triclosan, however, which is needed for the risk assessment of triclosan. The US Food and Drug Administration (FDA) nominated triclosan to the National Toxicology Program (NTP) for toxicological evaluations. THe NTP conducted several dermal toxicological studies to determine the carcinogenic potential of triclosan, evaluate its endocrine and developmental-reproductive effects, and investigate the potential UV-induced dermal formation of chlorinated phenols and dioxins of triclosan (13). Triclosan is not currently known to be hazardous to humans, but several scientific studies have come out since the last time the FDA reviewed this ingredient that merit further review. Animal studies, for example, have shown that triclosan alters hormone regulation (keep in mind that data showing effects in animals don’t always predict effects in humans, which is why animal testing is often ineffective and outdated). Other studies have raised the possibility that triclosan contributes to making bacteria resistant to antibiotics. The compound’s widespread use in consumer products and its detection in breast milk, urine, and serum have raised concerns regarding its potential association with various human health outcomes. Recent evidence suggests that triclosan may play a role in cancer development, perhaps through its estrogenicity or ability to inhibit fatty acid synthesis (14), although human studies are lacking in both number and scope. It is also very toxic to the aquatic environment. Therefore, epidemiologic studies of risk associated with various concentrations and durations of exposure to triclosan are needed, as well as studies to characterize human exposure to triclosan through varying use of triclosan-containing consumer products and other routes of exposure. In light of these studies, the FDA is engaged in an ongoing scientific and regulatory review of this ingredient. FDA does not have sufficient safety evidence to recommend changing consumer use of products that contain triclosan at this time, however the avoidance of it may be a good idea just in case it does affect hormones (which can affect acne).
Look for: TRICLOSAN; TRICLOCARBAN
3. Sodium hydroxide
Sodium hydroxide (NaOH) solutions with a pH of 11.5 or greater should be considered corrosive to the skin (15). Less concentrated solutions of NaOH, such as those found in skin care products, although not corrosive, can be irritating to the skin. Nagao et al. (16) noted total destruction of the epidermis in 60 minutes in skin biopsies of volunteers who had 1-normal (N)* NaOH applied to their forearms for 15 to 180 minutes. A study conducted by Seidenari et al. (17) showed that a 4% aqueous NaOH solution caused an enhanced inflammatory response with pronounced barrier function damage. Agner and Serup (1987) reported that a 2% aqueous solution of NaOH applied to the skin of volunteers caused severe crusting in some volunteers but no inflammation in others. This is unsurprising as NaOH is alkaline, and our skin is acidic. Studies have shown that alkaline skin care products applied to healthy skin increases trans epidermal water loss (TEWL), and may be more sensitive to external stressors (19). These results suggest significant variability in the corrosivity of NaOH to human skin. Repeated applications of NaOH are more likely to produce skin damage, but it is unlikely that repeated application of nonirritating concentrations of NaOH can produce systemic effects, given that such exposures would not significantly increase the concentration of sodium in the blood or increase the pH of the blood. Thus, "soap" products,
Look for: CAUSTIC SODA; SODIUM HYDROXIDE; SODIUM HYDRATE; SODIUM HYDROXIDE (NA (OH) ) ; SODIUM HYDROXIDE SOLUTION; LEWIS-RED DEVIL LYE; SODA LYE
(Commercial "soap" bars and handmade soap bars are also made with lye even though the words "sodium hydroxide" or "lye" do not appear on the labels. Does your bar of "soap" contain ingredients such as: saponified oils: oils and butters are mixed with sodium hydroxide and a liquid (usually water); sodium cocoate: the generic name for the mixture of coconut oil with sodium hydroxide (lye); sodium palmate: the generic name for the mixture of palm oil with sodium hydroxide (lye); sodium palm kernelate: the generic name for the mixture of palm kernel oil with sodium hydroxide (lye); sodium tallowate: the generic name for the mixture of beef fat (tallow) with sodium hydroxide (lye); sodium olivate: the generic name for the mixture of olive oil with sodium hydroxide (lye)?)
4. Sodium Lauryl Sulfate
Often referred to as ‘SLS’, this ingredient is a powerful foaming agent and detergent which is why it is so frequently used in personal care products such as shampoo, toothpaste, hand soap, shaving cream, body washes, conditioners, and bath foams. You will also find it in foaming cleansers and some other unlikely places.
Health Canada, the European Union and the U.S. Food and Drug Administration (FDA) consider SLS and SLES to be safe ingredients, as does The Cosmetic Ingredient Review, an independent U.S. organization that assesses the safety of ingredients in cosmetics. However, it isn't necessarily the concern of toxicity so much as it is the concern for what it can do to your skin's overall health and resilience.
SLS may not only increase TEWL (20) but it is also a very common irritant. In fact, it is even used in studies to provoke skin irritation (19). SLS is an ingredient you may especially want to avoid if your skin is easily irritated or already damaged.
Look for: SODIUM LAURYL SULFATE; DODECYL SODIUM SULFATE; SLS; SULFURIC ACID MONODODECYL ESTER SODIUM SALT; SODIUM DODECANESULFATE; DODECYL ALCOHOL; HYDROGEN SULFATE; SODIUM SALT; AKYPOSAL SDS
Related chemicals include sodium laureth sulfate, or SLES, which has a higher foaming ability and is slightly less irritating than SLS. Ammonium lauryl sulfate, or ALS, is similar to SLS and poses similar risks.
The diesters of 1,2-benzenedicarboxylic acid (phthalic acid), commonly known as phthalates, are a group of man-made chemicals widely used in industrial applications. They are primarily used as plasticizers in the manufacturing of flexible vinyl plastic which, in turn, is used in consumer products, flooring, and wall coverings, food contact applications, and medical devices. They are also used in personal-care products (e.g., perfumes, lotions, cosmetics), as solvents and plasticizers for cellulose acetate, and in making lacquers, varnishes, and coatings, including those used to provide timed releases in some pharmaceuticals (1)(2)(3).
Human exposure to phthalates is widespread and occurs through ingestion, inhalation, and dermal contact (2)(3)(4)(5)(6)(7). Parenteral exposure from medical devices and products containing phthalates are important sources of high exposure to phthalates, primarily di-(2-ethylhexyl) phthalate (DEHP) (5)(8). Phthalates have biological half-lives measured in hours, are rapidly metabolized, and are excreted in urine and feces (2)(3)(4)(5). The most common biomonitoring approach for investigating human exposure to phthalates is the measurement of urinary concentrations of phthalate metabolites.
There are few epidemiological studies on phthalates and semen quality. A large study on male partners of subfertile couples from an infertility clinic in Massachusetts (9)(10) found associations between monobutyl phthalate and below World Health Organization (WHO) reference value sperm motility and sperm concentration. There was also a dose-response relationship between monobenzyl phthalate and below WHO reference value sperm concentration. In contrast to the U.S. study, in a Swedish study there were no relationships of MBP or MBzP with any of the semen parameters (11). Potential reasons explaining why the two studies found differing results include differences in age and fertility of the study populations. The Swedish study population consisted of young men (median age, 18 yr; range, 18–21 yr) from the general population, whereas in the U.S. study the median age of the men from an infertility clinic was 35.5 yr and ranged from 22 to 54 yr. None of the men from the infertility clinic were 21 yr of age or younger. Men presenting to an infertility clinic may be more “susceptible” to reproductive toxicants, including phthalates, than men from the general population. Furthermore, it is also unclear whether middle-aged men, compared with young men, are more susceptible to reproductive toxicants because of an age-related response to the toxicant.
A growing number of studies indicate that chemical family damages the male reproductive system. Pregnant women should avoid nail polish containing dibutyl phathalate. Everyone should avoid products with “fragrance” indicating a chemical mixture that may contain phthalates.
Not to mention that fragrance allergies are really common. Some people might develop a skin rash or hives from musk, while others react to vanilla scents.
Even though some organizations suggest that phthalates are generally recognized as safe, it may be best to avoid them in light of the fact that they seem to be endocrine disruptors.
Look for: PHTHALATES, FRAGRANCE, PARFUM
Oxybenzone is a sunscreen ingredient associated with photoallergic reactions. This chemical supposedly absorbs through the skin in significant amounts; it contaminates the bodies of 97% of Americans according to research by the Centers for Disease Control and Prevention.
Look for: BENZOPHENONE-3, (2-HYDROXY-4-METHOXYPHENYL) PHENYL- METHANONE; (2-HYDROXY-4-METHOXYPHENYL) PHENYLMETHANONE; 2-BENZOYL-5-METHOXYPHENOL; 2-HYDROXY-4-METHOXYBENZOPHENONE; 4-08-00-02442 (BEILSTEIN HANDBOOK REFERENCE) ; 4-METHOXY-2-HYDROXYBENZOPHENONE; ADVASTAB 45; AI3-23644; ANUVEX; B3; BENZOPHENONE, 2-HYDROXY-4-METHOXY-
According to data from the federal Food and Drug Administration, nearly 1 in 5 cosmetic products contains a substance that generates formaldehyde, a known human carcinogen. The U.S. government and World Health Organization have classified formaldehyde as carcinogenic when its fumes are inhaled. It is also a potent skin sensitizer and allergen. But you won't find formaldehyde on your ingredients list; cosmetics companies don’t dump pure formaldehyde into their concoctions. Instead, they take a roundabout route by using what they call “preservative systems” that employ any one of several chemicals, called “formaldehyde releasers.” These are chemicals that, when added to water, will decompose slowly over time to form molecules of formaldehyde. Some manufacturers favor this method because it acts like a time-release capsule, maintaining a fairly constant level of preservative in the mix. The reactions that generate formaldehyde occur silently as the products sit on shelves in stores or bathroom cabinets.
The cancer risks presented by a cosmetic could be considered slight -- but that product is not a person’s only source of exposure. People are also exposed to formaldehyde by pressed-wood products, cigarette smoke, vehicle exhaust and unvented fuel-burning appliances such as gas stoves, wood-burning stoves and kerosene heaters; Personal care products that contain formaldehyde make an unnecessary contribution to an individual’s exposure to this chemical – particularly since research shows that cosmetic products can release small amounts of formaldehyde into the air shortly after they are applied. Formaldehyde is most dangerous when inhaled. Formaldehyde made the Mayo Clinic's top 10 list of contact dermatitis allergens.
Look for: DMDM hydantoin; Imidazolidinyl urea; Diazolidinyl urea; Quaternium-15; Bronopol (2-bromo-2-nitropropane-1,3-diol ); 5-Bromo-5-nitro-1,3-dioxane; Hydroxymethylglycinate
You may be familiar with papain as a natural enzyme found in papaya - many enzyme exfoliants use papain in their products for its unique chemical exfoliating properties. However, a recent study showed that papain induces a breakdown of cell-cell junctions. On the skin, papain results in a loss of the barrier function. After just a short period of time, papain increases vascular permeability and inflammatory cells infiltrate the skin. But the permeation of the skin barrier does not appear to be a prerequisite for sensitization toward papain. The enzyme remains allergenic even when its enzymatic function has been blocked; the disruption to the skin barrier is essential for the infiltration of other allergens and bacteria. It is striking that papain has an enormous structural similarity with one of the most important house dust mite allergens. Sensitization toward these house dust mite allergens follows the same principle. Thus, people with sensitive skin as well as small children should avoid the enzyme papain as much as possible, and observe the ingredients in their skin care products.
Look for: PAPAIN; papaya proteinase I
9. Neomycin sulfate
This is a topical antibiotic common in first aid creams and ointments, also found occasionally in cosmetics, deodorant, soap and pet food. It made the Mayo Clinic's top 10 list of contact dermatitis allergens, and was declared the Contact Allergen of the Year for 2010 by the American Contact Dermatitis Society (ACDS). In neomycin allergic individuals, contact with neomycin from topical preparations produces classic allergic contact dermatitis reactions. Prolonged or repeated use may cause an inflamed, weepy rash in the affected area. It is thought that individuals that suffer from atopic dermatitis may be more sensitive to neomycin, and yet atopic dermatitis is often treated with topical combination preparations of neomycin and corticosteroids.
10. Quaternium 15
This is a preservative found in cosmetic products such as self-tanners, shampoo, nail polish and sunscreen or in industrial products such as polishes, paints and waxes. It is also especially common in foundations, powders, concealers, eye makeup (liners, shadows, mascara), facial makeup (blushes), bronzers, makeup removers, cleansers and moisturizers. It also made the Mayo Clinic's top 10 list of contact dermatitis allergens. It is one of the formaldehyde-releasing preservatives mentioned earlier, although it is particularly notable due to it being such a common dermatitis allergen.
Look for: Azonium-adamantane chloridN-(3-chloroallyl) hexaminium chloride; Chloroallyl methenamine chloride1-(3-chloroally)-3,5,7 triaza-1-azoniaadamantane chloride; Methanamine-3-chloroallylochloride; Hexamethylenetetramine; Dowicil®75; Dowicil®100; Dowicil®200
MI is a chemical preservative that is found in many water-based products like liquid soaps, hair products, sunscreen, lotions, cosmetics, laundry products and cleaners as well as pre-moistened personal hygiene products and baby wipes. Concentrations of the preservative have increased dramatically in some products in the last few years, as manufacturers stopped using other preservatives like paraben and formaldehyde. Exposure to MI can lead to irritated skin that can be red, raised, itchy and even blistery, appearing much like a reaction to poison ivy. The three most common areas affected by the allergic reaction include the face, from using soaps and shampoos, the fingers and hands, from handling the wipes, and the buttocks and genitals from using moistened flushable wipes. Even products labeled as "sensitive" or "organic" may contain MI. While it is banned in some places, it is merely restricted in Canada, and in the U.S. meaning it is still in use.
Look for: 2-METHYL- 3 (2H) -ISOTHIAZOLONE; 2-METHYL-2H-ISOTHIAZOL-3-ONE; 2-METHYL-3 (2H) -ISOTHIAZOLONE; 2-METHYL-4-ISOTHIAZOLIN-3-ONE; 3 (2H) -ISOTHIAZOLONE, 2-METHYL-; 3 (2H) ISOTHIAZOLONE, 2METHYL; METHYLCHLOROISOTHIAZOLINONE225METHYLISOTHIAZOLINONE SOLUTION; 2-METHYL-3 (2H) -ISOTHIAZOLONE; 2-METHYL-4-ISOTHIAZOLIN-3-ONE
Other common ingredients that may be the culprit for your skin irritation are ascorbic acid, paraben preservatives, and alpha hydroxy acids such as glycolic acid, malic acid, and lactic acid. However, these ingredients are not always irritating and should be evaluated on a case-by-case basis. Keep in mind that just because something is considered a common irritant does not mean it will necessarily irritate your skin. It simply means that if you have skin care products with those ingredients + skin irritation, it may be a culprit.
Allergen avoidance is obviously the chief treatment for contact dermatitis. However, if you do develop a contact allergy or irritation corticosteroid creams are generally used to treat these rashes. However, 3 percent of patients with contact dermatitis are allergic to the topical steroids that would alleviate their symptoms!
Let me know what you thought of this article by leaving your comment below! Do you read the labels on your skin care products? Are there certain ingredients that you avoid that I didn't list that you would like me to look into or list here?
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