What's The Difference Between 'SPF' & 'Broad Spectrum'?

By Stef Crowley-Clough

What's the difference between SPF 50+ & SPF 50+ Broad Spectrum?

SPF stands for Sun Protection Factor and it measures your sunscreen’s ability to protect your skin from UVB rays. It basically refers to how long the sunscreen will protect you before you start to burn (sunburn = sun damage).

Sunscreen with an SPF of 15 will prevent your skin from getting red for approximately 15 times longer than usual (so if you start to burn in 10 minutes, sunscreen with SPF 15 will prevent burning for about 150 minutes).

Click here to read more about SPF and the difference between SPF 15, 30 & 50.

UVB however, is not the only UV ray that causes sun/skin damage. Drum roll… introducing the silent & very nasty UVA spectrum of rays.

Both UVA and UVB are forms of ultraviolet light that penetrate the earth's atmosphere (there are no sunscreens that can block 100% of these UV rays).

What’s the difference, you ask?

UVAs penetrate deep (deeper than UVB) into the skin’s dermis which is the skin's thickest layer. They are considered the sun’s silent killers because, unlike UVB rays, they are not painful, but those unfelt UVA rays wreak havoc on every layer of the skin and are responsible for premature aging, sun spots, collagen degeneration, pigmentation, hyperpigmentation, wrinkles and unfortunately, every type of skin cancer.

UVB is what generates a burn or redness to the skin, and ultimately skin cancer (both UVA & UVB can contribute to skin cancers and are key players in causing premature aging).

Here's a video from Dr. Scott McGregor

Image source.

So what does this mean in sunscreen terms?

Sunscreen can be SPF 50+ and not protect you from UVA rays. Most (all) ‘physical’ or ‘mineral’ sunscreen filters on their own, are not completely broad spectrum. Zinc Oxide for example, is an excellent UVB filter but it doesn't cover UVA1. 

And while we’re on the topic, we just wanted to touch on something...

There is a misconception about chemicals in sunscreen. There is no such thing as a “chemical-free” sunscreen. Everything and every organism is made of a combination of chemicals of some sort, even in the natural world. There are two types of filters used in sunscreen - physical (mineral) and active (chemical). Physical sunscreens often contain zinc oxide and titanium oxide, which are not typically found in nature, but rather created in a lab by oxidizing zinc and titanium metal.

Let’s re-cap.

1. There is no sunscreen that can block 100% of UV rays.

2. A sunscreen can be SPF50+ but unless it states that it is broad-spectrum, it will not be protecting you from the full array of damaging UVA rays.

So while we strongly encourage you to use a sunscreen with a 50+ SPF, we also don’t want you to be misled by the copious amounts of misinformation out there. Make sure you use broad-spectrum, your skin deserves it!