Possible Harmful Sunscreen Effects

Some sunscreen ingredients may cause:

  • Dryness of the skin
  • Irritant or allergic dermatitis
  • Photosensitivity
  • Acne
  • Skin ageing
  • Cancer
  • Other symptoms (after inhalation or ingestion of a sunscreen)

Ingredients That Dry Up the Skin

Sunscreen ingredients that dry up the skin:

  • Alcohol, Isopropyl (SD40) dries up the skin, promotes brown spots and premature skin aging (1).

Ingredients Causing Irritant or Allergic Dermatitis

Substances that may irritate the skin and mucosa or cause allergic reactions (eczema) (1):

  • Parabens are used as preservatives. They may cause skin rashes, redness, and pain, or, after inhalation, irritation of the eyes and the mucosa of the nose and throat.
  • Methylisothiazolinone and methylchloroisothiazolinone
  • Bronopol (2-bromo-2-nitropropane-1,3-diol)
  • Propylene/butylene glycol is derived from petroleum. It is used to extract substances from herbs.
  • Quaternium-7, -15, -31, -60, etc
  • Stearalkonium chloride

Ingredients Causing Photosensitivity

Some sunscreen ingredients, after exposure to the sun, may yield substances that may cause photosensitivity – a strong skin reaction, resembling sunburn (4):

  • PABA (para-aminobenzoic acid, rarely found in sunscreens today)
  • Benzophenones
  • Cinnamates
  • Salicylates
  • Fragrances: musk, 6-methylcoumarin

Ingredients Causing Acne

The following substances may cause acne:

  • Mineral oil and other petroleum derivatives, like liquidum paraffinum (posh mineral oil), paraffin oil, paraffin wax, and petrolatum, clog pores, thus promoting acne (1).

Ingredients Causing Skin Ageing

Skin ageing is mainly caused by UVA rays. Prolonged, repeated exposure to the sun, when using any sunscreen product without sufficient UVA filtering, may result in skin ageing. The following sunscreen ingredients may also cause skin ageing (1):

  • Mineral oil and related products

Ingredients Causing Cancer

The following substances were found to cause cancer (1):

  • TEA, DEA, MEA (tri-, di- and mono- ethaloamines) can cause liver and kidney cancer. They are also corrosive to the eyes, and cause allergic reactions.
  • Formaldehyde is carcinogenic. It is strongly irritant to the eyes and throat and causes irritant and allergic dermatitis.
  • Diazolidinyl and imidazolidinyl urea (Germall 115) may release formaldehid, so it is irritant and carcinogenic.
  • Most of FD&C color pigments are carcinogenic (according to animal studies). They also contain heavy metals that may cause skin sensitivity.
  • The following nitrosating agents were proven to cause cancer in laboratory animals:
    • 2-bromo-2-nitropropane-1,3-diol
    • Cocoyl sarcosine
    • Hydrolysed animal protein
    • Lauryl sarcosine
    • Quaternium-7, 15, 31, 60, etc
    • Sodium lauryl sulfate (SLS), ammonium lauryl sulfate (ALS), sodium laureth sulfate (SLES), ammonium laureth sulfate (ALES)
    • Sodium methyl cocoyl taurate
  • Lanolin is obtained from the wool, so it is often contaminated with chemicals used on sheep (pesticides).
  • Mineral oil can be contaminated with PAHs (polycyclic aromatic hydrocarbons) that cause cancer.
  • Talc, routinely used in genital area, increases the risk of ovarian cancer.

Ingredients Causing Other Symptoms

Symptoms of a damage of internal organs may be caused by (1):

  • Fragrances (substances that give the smell to the cosmetic product). Their exact composition is usually not revealed on labels, but one or more of several thousands substances may be included. They may cause headache, dizziness, allergic rashes, skin discoloration, violent coughing and vomiting, depression, hyperactivity and irritability.
  • Propylene/butylene glycol is derived from petroleum and is used to extract substances from herbs. It is highly toxic and may cause eye, nose and throat irritation (after inhalation), neurological and blood disorders and pulmonary edema.

Nanoparticles in Sunscreens

Nanoparticles are particles 1-100 nanometers in size (1 nanometer is one millionth of millimeter). They usually represent particles of zinc oxide and titanium dioxide that were broken down to prevent opacity and thickness of sunscreen. According to Environmental Working Group, nanoparticles do not represent damage to the human body if used on intact skin (2). Australian Therapeutic Goods Administration claims the same (3).

Cosmetic Ingredients, Prohibited or Restricted by FDA

USA Federal Drug Administration (FDA) prohibits or restricts use of the following ingredients in cosmetics (they rarely appear in sunscreens, though):

  • Prohibited ingredients:
    • Bithionol  – may cause photosensitization.
    • Chlorofluorocarbon propellants.
    • Chloroform – was determined as cancerogenous in animal tests. Residual amounts from its use as a processing solvent are allowed.
    • Halogenated salicylanilides (di-, tri-, metabromsalan and tetrachlorosalicylanilide)  – may cause photosensitization.
    • Methylene chloride - determined as carcinogenic in animal tests.
    • Vinyl chloride  - prohibited in aerosol products, bacause it is carcinogenic.
    • Zirconium-containing complexes- prohibited in aerosol products because of their lung toxicity (granuloma formation).
    • Some cattle materials are prohibited to protect against bovine spongiform encephalopathy (BSE, ‘mad cow disease’). Allowed cattle materials are tallow, hides, milk and their derivates [21 CFR 700.27, as amended].
  • Restricted ingredients:
    • Hexachlorophene (HCP) may penetrate the skin, so its concentration in the product may not exceed 0.1 percent and may not be used in lipsticks.
    • Mercury compounds may be absorbed through the skin and cause allergic reactions or chronic neurological symptoms. Their concentration may not exceed 65 parts per million in eye area cosmetics or 1 part per million in other cosmetics.
    • If a sunscreens is used in cosmetics only “to protect the product color”, this has to be clearly denoted on the product label, otherwise a product labeled as “contains sunscreen” may be considered as a drug by FDA regulation.

Find a Safe Sunscreen

There is probably no sunscreen that is 100% safe, or 100% effective. Terms as “organic” or “natural” sunscreen are often misleading, and there is no complete list of harmful sunscreen ingredients, so checking an independent ranking of sunscreen products may help you to chose appropriate one.

References:

  1. Toxic skin care ingredients  (mionegroup.com)
  2. Are nanoparticles safe?  (cosmeticsdatabase.com)
  3. Nanoparticles safety according to TGA  (tga.gov.au)
  4. Sunscreen ingredients causing photosensitivity  (dermnetnz.org)

Article reviewed by Dr. Greg. Last updated on January 1, 2013