In Minnesota, we like to say we have 11 seasons — not four. They are:

  • Winter
  • Fool’s Spring
  • Second Winter
  • Spring of Deception
  • Third Winter
  • Mud Season
  • Actual Spring
  • Summer
  • False Fall
  • Second Summer
  • Actual Fall

Right now, we’re somewhere between Actual Spring and Summer, which means shelves are stocked with bug spray, sunglasses, and (of course) sunscreen. That got us thinking… how is sunscreen made?

Let’s break it down in this month’s How It’s Made feature.

What Does Sunscreen Do?

The sun emits three types of light: infrared, visible, and ultraviolet (UV). UV light is the most harmful to humans. There are two types of UV rays:

  • UVA: Can penetrate deep into the skin, damaging cells and the immune system
  • UVB: Can burn the outer skin and contribute to skin cancer

Sunscreen helps by either blocking UV rays or absorbing them before they penetrate the skin. To do this, sunscreen includes active ingredients such as:

  • Titanium Dioxide
  • Zinc Oxide
  • Avobenzone
  • Octisalate
  • Oxybenzone
  • Homosalate

These are mixed with liquids (like purified water), functional agents (emulsifiers, stabilizers), and skin-nourishing ingredients like Vitamin E.

Here’s a graph showing the ingredient percentages typically found in sunscreen.

Four Steps to Making Sunscreen

Step 1: Purify the Water

Sunscreen starts with reverse osmosis purification to ensure clean, contaminant-free water.

Step 2: Mix the Ingredients

Solids, powders, and flakes are added to large kettles or vats with purified water. Recipes outline exact measurements, time, temperature, and mixing speed.

Curious how similar this process is to other manufacturing operations? Check out our past articles:

Step 3: Transfer to Stainless Steel Tanks

Once mixed, the formula is pumped through sanitary piping into 1,000-gallon tanks inside sterile rooms.

Step 4: Fill & Package

From these tanks, sunscreen flows into pressurized filling machines via more stainless piping.

  • Bottles are fed in by conveyor
  • Nozzles fill, cap, and seal each bottle automatically
  • Products are then boxed, palletized, wrapped, and shipped

Choosing the Right Sunscreen

Manufacturing it may be straightforward. Buying it? Not always.

If you’re standing in the sunscreen aisle unsure what to choose, you’re not alone.
Here are two great resources:

And remember — no matter how many “seasons” your state has, wear sunscreen year-round.

Happy (and SAFE) Sunning!