Zinc Oxide

What is it?

Zinc oxide is an odorless, white powder that is naturally occurring in the mineral zincite. Because of its insolubility in water, zinc oxide has a number of practical uses and is commonly found in ceramics, pigments, foods, and first-aid tapes.

What does it do?

In personal care products, zinc oxide is often used in sunscreen, anti-dandruff shampoo, deodorant, and diaper cream.

In sunscreen applications, zinc oxide filters out UV rays, helping to keep them from penetrating the skin and causing cell damage. It is the broadest spectrum UVA and UVB reflector that is approved for use as a sunscreen by the FDA. When used as an ingredient in sunscreen, zinc oxide helps block both UVA and UVB rays of ultraviolet light. Zinc oxide and the other most common inorganic sunscreen, titanium dioxide, are considered to be non-irritating, nonallergenic, and non-comedogenic.

In skin protectant applications, like a diaper cream, zinc oxide forms a protective barrier on the skin to help treat and prevent various skin conditions including minor abrasions, burns, chafing, diaper rash, insect bites, and minor skin irritation.

Zinc Oxide (ZnO) is a natural mineral that has been used for centuries in deodorant products.1 When we sweat, our natural skin bacteria multiply by feeding off the materials in sweat. The natural bacteria, and the new ones that appear, interact with components in sweat to create new molecules that are responsible for the unpleasant odors that people sometimes experience. ZnO works effectively to help reduce odor causing bacteria by minimizing the growth of new bacteria.  The effectiveness of ZnO has thoroughly been investigated and validated by many researchers. Our specially designed formula with ZnO delivers 48 hour odor protection.2345

How is it made?

Our Stewardship Model guides us to select ingredients which have been processed in a manner that supports our philosophy of human and environmental health.

Zinc metal is heated to a molten state and then superheated to create a pure zinc vapor which leaves other impurities behind. The zinc vapor is directed into a special reactor where it readily reacts with oxygen in the air in a combustion reaction to form the zinc oxide powder. The powder is collected and screened for size and removal of any additional impurities.

What are the alternatives?

Sunscreens are regulated by the Food and Drug Administration and while there are many active ingredients that are recognized by FDA for use in sunscreen6, there are very few that meet Tom’s Stewardship Model standards as many are synthetic derivatives of petroleum-based ingredients.

Skin protectants are also regulated by the Food and Drug Administration and while there are many other ingredients recognized as skin protectants, many of the commonly used alternatives like dimethicone, mineral oil, and white petrolatum don’t meet Tom’s Stewardship Model standards as they are synthesized and/or derivatives of petroleum-based ingredients.

In deodorants there are other ingredients that can help reduce odor-causing bacteria , such as sodium bicarbonate and hops. We use hops for this purpose in some of our long lasting deodorants. Additionally there are synthetic options, such as triclosan, but these would not meet our stewardship model.

Is this the right option for me?

Zinc oxide is recognized as safe and effective by the Food And Drug Administration for its stated uses in their respective levels.7

Tom’s of Maine recognizes that no two people are alike, and even with naturally derived ingredients, some individuals may develop an allergic reaction that is unique to them. As with any product, be sure to discontinue use if you experience discomfort or other indications that the product may not be appropriate for your individual body chemistry.

1 Joey Green (2004). "The Apothecary: Elixers, Remedies, and Tonics". Joey Green's Incredible Country Store: Potions, Notions and Elixirs of the Past--and How to Make Them Today (1 ed.). Rodale Books. p. 356. ISBN 978-1-57954-848-3.

2 S. Atmaca, K. Gül, R. Çiçek. The effect of zinc on microbial growth. Turk. J. Med. Sci., 28 (1998), pp. 595-597

3W. Jiang, H. Mashayekhi, B. XingBacterial toxicity comparison between nano- and micro-scaled oxide particles . Environ. Pollut., 157 (2009), pp. 1619-1625

4M. Li, L. Zhu, D. Lin Toxicity of ZnO nanoparticles to Escherichia coli: mechanism and the influence of medium components Environ. Sci. Technol., 45 (2011), pp. 1977-1983

5Yousef, J.,  In Vitro Antibacterial Activity and Minimum Inhibitory Concentration of Zinc Oxide and Nano-particle Zinc oxide Against Pathogenic Strains, Journal of Health Sciences 2012, 2(4): 38-42

621 CFR 352.10

721 CFR 182.5991 and 21 CFR 182.8991