"A practical supplier guide to zinc oxide (CAS 1314-13-2, OZn): spec-sheet data, sunscreen and skin-care use, rubber/coating/ceramic applications, handling and buyer notes, and how it pairs with squalane, glycerin, Alpha-Arbutin, and L-Ascorbic Acid."

-Deshangchemical-chemechemi

Zinc Oxide (CAS 1314-13-2): The Physical UV Filter That Does More Than Block Sun

Zinc oxide has been a standard industrial raw material for more than a century, yet it still sits on most formulators' shortlists — particularly for sunscreens, baby care, and skin protectants. Unlike chemical UV absorbers that soak up specific wavelengths, zinc oxide is a physical (mineral) filter: it stays near the surface and reflects and scatters both UVA and UVB radiation. This article looks at what the specification sheet actually says, how buyers use the material across cosmetics, rubber, and pharma, and what to check before placing an order.

What the spec sheet says

Before anything else, here is the data buyers ask about first:

CAS number	1314-13-2
Molecular formula	OZn
Molecular weight	81.39 g/mol
EINECS	215-222-5
Form	Nano powder
Melting point	1975 °C
Boiling point	1949.9 °C (estimated)
Density	5.6 g/cm³
Solubility in water	1.6 mg/L at 29 °C
Color	White to light yellow
Storage temperature	+5 °C to +30 °C

The numbers explain why zinc oxide behaves the way it does. It is practically insoluble in water, dense, and stable at very high temperatures — a mineral in the literal sense. For cosmetic use, a "nano powder" grade with a particle size around 0.1 µm is what gives the broad-spectrum scattering effect without leaving a heavy white cast.

Why formulators reach for it in skin care

In a sunscreen or daily moisturizer, zinc oxide earns its place because it covers the full UV range. Chemical filters tend to be narrow; a single zinc oxide grade can carry a meaningful share of both UVA and UVB protection. That is why it appears in so many "mineral" and "reef-safe" claims, and why pediatric and sensitive-skin lines lean on it. It is also listed as GRAS by the FDA (§182.8991), which keeps the regulatory story simple for food-adjacent and topical applications.

The material also turns up in classic dermatological preparations: zinc paste, calamine lotion, and the rubber-plaster style bandages used for minor skin protection. Its mild astringent and skin-soothing character is the reason it has stayed relevant long after newer actives appeared.

Pairing matters. A zinc oxide suspension feels dry on its own, so formulators build it into an oil phase with an emollient such as squalane and a humectant such as glycerin to keep the finish comfortable. A preservative booster like ethylhexylglycerin helps keep the whole system stable once water is present.

Beyond cosmetics: rubber, coatings, and ceramics

Skin care is only one slice of demand. In rubber, zinc oxide is a vulcanizing activator and reinforcing agent — it gives natural rubber better tear resistance and elasticity and acts as a coloring and filling agent for white compounds. In plastics such as polyolefins and PVC, fine grades (particle size near 0.1 µm) work as light stabilizers that slow weathering. As an inorganic white pigment it is used in paints, inks, ABS, polystyrene, epoxy, and phenolic resins, sitting just below titanium dioxide in tinting strength but valued for cost and coverage.

It also serves the electronics and ceramics side: electrostatic copying, laser fax, and static-recording media; special functional coatings; and newer chiral framework materials such as NaZnSiO3OH for ion exchange, adsorption, or catalysis. In refining, it supports deep desulfurization and purification of oil, ammonia, methanol, and hydrogen streams.

Handling, storage, and what to check before you buy

Zinc oxide is stable and easy to handle, but a few points keep a batch on spec:

• Keep it dry. Store at +5 °C to +30 °C in a sealed container; although the material itself is stable, clumping from moisture complicates weighing and dispersion.
• Match the grade to the job. Cosmetic and sunscreen work needs a tight particle-size distribution and a clean heavy-metal profile; rubber and coatings can accept broader specifications.
• Ask for the test report. Every batch should come with a COA and, for topical use, heavy-metal and microbial limits. A supplier that runs per-batch testing saves rework downstream.
• Note the toxicology. Oral LD50 in rats (intraperitoneal) is 240 mg/kg, and the material is GRAS for defined food uses. Standard industrial PPE is enough for powder handling; avoid prolonged dust inhalation.

How it fits with the rest of your formula

Zinc oxide rarely works alone. In a skin-care line it sits naturally alongside brightening and conditioning actives: Alpha-Arbutin for tone, L-Ascorbic Acid as an antioxidant, and N-Acetyl-D-Glucosamine for hydration support. Humectants such as urea and trehalose dihydrate round out the moisturizing base that makes a mineral filter feel less chalky.

Supplier note

We supply zinc oxide (CAS 1314-13-2) directly from Shandong Deshang Chemicals Co., Ltd., with sample testing and per-batch QC. If you are scoping a sunscreen, rubber, or ceramic formulation and need a specific particle size or grade, get in touch and we will match the spec to the application.