Oxybenzone in Skincare

Oxybenzone in Skincare: A Critical Examination of Its Role, Risks, and Controversies

Oxybenzone, a widely used chemical in sunscreens and personal care products, has been a subject of intense debate in the cosmetic and dermatological industries. While it is recognized for its ability to absorb UV radiation and protect against sun damage, concerns regarding its potential health risks and environmental impact have led to increased scrutiny and regulatory changes worldwide. This article delves into the chemical composition, manufacturing process, function in skincare formulations, and the debated health and environmental effects of oxybenzone.


What Is Oxybenzone?

Oxybenzone, also known as benzophenone-3, is an organic compound classified as a benzophenone derivative. Its primary function in skincare and sunscreen formulations is as a broad-spectrum UV filter, capable of absorbing UVB and some UVA rays, thus helping to prevent sunburn and long-term skin damage.

Chemical Profile of Oxybenzone

  • IUPAC Name: 2-Hydroxy-4-methoxybenzophenone
  • Molecular Formula: C₁₄H₁₂O₃
  • Molecular Weight: 228.24 g/mol
  • Solubility: Soluble in organic solvents such as ethanol and oils; limited solubility in water
  • Appearance: White to pale yellow crystalline powder

Key Properties

  • UV Absorption: Absorbs wavelengths between 270-350 nm, offering UVB and partial UVA protection.
  • Photostability: Often used with other stabilizers to prevent photodegradation.
  • Lipophilic Nature: Allows it to penetrate the skin and mix with the lipid layers.

How Is Oxybenzone Manufactured?

Oxybenzone is synthesized via a Friedel-Crafts acylation reaction, a common process in organic chemistry used for creating benzophenone derivatives.

Manufacturing Process

  1. Reaction of Resorcinol with Benzoyl Chloride

    • Resorcinol (C₆H₄(OH)₂) undergoes an acylation reaction with benzoyl chloride (C₆H₅COCl) in the presence of a Lewis acid catalyst, such as Aluminum chloride (AlCl₃).
  2. Methoxylation

    • The hydroxyl (-OH) group at the para-position is methylated using methyl iodide (CH₃I) to improve lipophilicity and stability.
  3. Purification and Crystallization

    • The crude product is purified using solvent extraction and recrystallization, ensuring a high degree of purity for cosmetic and pharmaceutical applications.

This industrial synthesis method allows for mass production of oxybenzone at a relatively low cost, making it one of the most economical UV filters available in the personal care industry.


Why Is Oxybenzone Used in Skincare?

Despite increasing concerns over its safety profile, oxybenzone continues to be used in sunscreens and cosmetic products due to its UV-filtering ability. Here’s why manufacturers include it in formulations:

1. UV Protection

Oxybenzone absorbs UVB radiation (280–320 nm) and part of the UVA spectrum (320–400 nm), preventing DNA damage and photoaging. While it does not cover the full UVA range, it is often combined with avobenzone, octinoxate, or zinc oxide for broad-spectrum coverage.

2. Stability in Formulations

Compared to some UV filters, oxybenzone is relatively photostable when used with stabilizing agents. This means it does not degrade quickly under sunlight, maintaining its protective efficacy longer.

3. Low Cost and Easy Formulation

As a synthetic, oil-soluble compound, oxybenzone integrates easily into emulsions, creams, and lotions, making it a preferred choice for formulators seeking to create effective sunscreens at lower costs.

4. Cosmetic Appeal

Unlike physical UV blockers such as zinc oxide and titanium dioxide, oxybenzone does not leave a white cast, making it popular in products designed for daily use and diverse skin tones.


Effects on Consumers: Benefits vs. Risks

While oxybenzone provides sun protection, it has been associated with potential health risks and environmental concerns, prompting increasing regulation.

1. Skin Penetration and Absorption

Unlike mineral sunscreens, oxybenzone is a lipophilic molecule, meaning it can penetrate the skin and enter the bloodstream. Studies have detected oxybenzone in urine, blood plasma, and even breast milk, raising concerns about bioaccumulation.

2. Potential Hormonal Disruption

Oxybenzone has been identified as an endocrine disruptor, meaning it may interfere with the body's hormone systems. Some animal and in vitro studies suggest that it may:

  • Mimic estrogen activity
  • Alter thyroid hormone levels
  • Affect reproductive health in both males and females

However, human studies remain inconclusive, with regulatory agencies arguing that exposure levels from sunscreen use are too low to cause significant health effects.

3. Allergic Reactions and Skin Sensitivity

Oxybenzone has been classified as an allergen, with photoallergic contact dermatitis being one of the most reported reactions. Those with sensitive skin may experience:

  • Redness
  • Burning sensation
  • Skin irritation

Due to these concerns, dermatologists often recommend oxybenzone-free sunscreens for individuals prone to eczema or rosacea.

4. Potential Carcinogenic Concerns

Some studies have linked UV filter chemicals, including oxybenzone, to DNA damage and oxidative stress, which could theoretically contribute to carcinogenesis. However, no conclusive human data links oxybenzone use to cancer risk.

5. Environmental Impact

Oxybenzone is highly toxic to marine ecosystems, particularly coral reefs. It has been shown to cause:

  • Coral bleaching by disrupting symbiotic algae
  • DNA damage in marine organisms
  • Endocrine disruption in fish and amphibians

Due to these findings, Hawaii, Key West, and Palau have banned sunscreens containing oxybenzone, pushing the industry toward reef-safe alternatives.


Regulatory Status and Industry Response

Bans and Restrictions

  • EU & Japan: Limited concentration (up to 6%) in sunscreens
  • Hawaii & Key West: Banned in sunscreen formulations (2018)
  • FDA (USA): Requires additional safety data but has not banned the ingredient

Shifts in the Industry

Due to consumer backlash, many brands are phasing out oxybenzone in favor of:

  • Zinc oxide & titanium dioxide (mineral sunscreens)
  • Tinosorb S & M (new-generation chemical filters)
  • Mexoryl SX & XL (photostable, FDA-approved alternatives)

Takeaway:

Oxybenzone remains one of the most controversial ingredients in skincare. While it effectively absorbs UV radiation and provides broad-spectrum sun protection, concerns over hormonal disruption, skin absorption, allergic reactions, and environmental toxicity have led to increasing regulatory restrictions and consumer preference for oxybenzone-free sunscreens.

As the cosmetic industry moves toward safer and more sustainable UV filters, it is likely that oxybenzone will continue to decline in popularity, replaced by better-formulated, reef-safe alternatives that prioritize both human health and environmental preservation.

Consumers should remain informed about ingredient choices, particularly when selecting sunscreens for daily use, and consider safer, non-toxic alternatives for long-term skin and health benefits.