Center for Research on Ingredient Safety

What is zinc oxide and where does it come from?

Zinc oxide powder is a fine white substance derived from the naturally occurring mineral zincite. We use this powder in many cosmetics, foods, and even household products.

What products contain zinc oxide?

Zinc oxide used in the proper refined form and in specific formulations can be found in many common products including sunscreen, calamine lotion, astringent, breakfast cereals, paint, and more.

What properties does zinc oxide possess?

Zinc oxide has a host of properties, below are common household products and the role that zinc oxide plays as an important ingredient.

• Sunscreen –  Zinc oxide works as an excellent physical sunscreen, meaning it lays on our skin in a thin layer and reflects harmful UVA and UVB rays without absorbing into our skin. Thus, providing robust protection against the sun’s harmful rays. 
• Calamine lotion –  Zinc oxide works with other active ingredients to provide a barrier that helps dry skin that’s weeping from poison ivy, poison oak, or poison sumac. It even has antimicrobial properties that can help keep germs at bay.
• Astringent – Zinc oxide works as an astringent meaning it helps shrink skin and pores and can absorb excess oils. This can reduce acne and help keep our skin dry in the summer heat.
• Breakfast cereal – Zinc oxide helps safely fortify breakfast cereals and other foods to make sure we’re getting the nutrients we need.
• Paint – Zinc oxide’s white color and reflective properties make it a great pigment in many household paints.

What are the documented risks? 

If you inhale a significant quantity of zinc oxide, more than you would encounter in daily life, you can become ill. This is extremely rare and typically occurs in industrial settings rather than in our home lives.

Additionally, allergic responses to zinc oxide have been reported but these cases are also very rare.

What’s the emerging concern? 

While zinc oxide has been used in many capacities since ancient times, recently we’ve seen concerns raised around zinc oxide nanoparticles*. 

People are worried these nanoparticles will cause adverse reactions to our health and wellness due to their size and shape and how they can potentially interact with our bodies.

We know that zinc oxide nanoparticles are both naturally occurring during mining and processing, as well as created by humans with the intention of creating a better product typically in sunscreens and other cosmetics (1).

*Nanoparticles are particles that are extremely small, for example, the thickness of one piece of paper is approximately 100,000 nanometers. Check out https://htwins.net/scale2/ to help visualize this scale in terms of everyday, familiar objects and concepts. 

What’s the risk? 

We know that zinc oxide often serves as the active ingredient in SPF-containing cosmetic products and sunscreens designed to help minimize the damaging impact of sun exposure.  

We know the current literature does not show any adverse health outcomes from nano-sized zinc oxide particles found in cosmetics or sunscreens.

We do know the risks of not using sunscreen and sunscreen-containing products far outweigh the risks of using them. We know exposure to UVA and UVB rays can increase your risk of developing

• Skin cancers, including basal cell carcinoma, squamous cell carcinoma, melanoma, and more.
• Premature skin aging.
• Cataracts. 

According to The Skin Cancer Foundation

• 1 in 5 Americans will develop skin cancer by the age of 70.
• More than 2 people die of skin cancer in the U.S. every hour.
• Having 5 or more sunburns doubles our risk for melanoma.
• More people are diagnosed with skin cancer each year in the U.S. than all other cancers combined.
• About 90 percent of non-melanoma skin cancers are associated with exposure to ultraviolet (UV) radiation from the sun. 

We know using sunscreen and sunscreen-containing products, including products with nano-sized zinc oxide, regularly and as directed can help decrease our risk of developing adverse health outcomes from repeated sun exposure and sunburns. 

Taking these statistics into consideration, we can easily see how the risks of repeated sun exposure and sunburns far out weights the risks of a potential adverse outcome due to nano-sized zinc oxide found in sunscreen and sunscreen-containing products.

The good news.

Zinc oxide is a highly versatile ingredient we’ve safely used for millennia. We know that we can continue to safely enjoy zinc oxide’s properties in all forms.

If you have any questions about foods and ingredients, please reach out to us on Twitter, send us an email, or submit your idea to us at go.msu.edu/cris-idea.