---
title: "Sunscreen Basics for SPF and Broad Spectrum"
url: https://www.herewashingtondc.com/2026/11/11/sunscreen-basics-for-spf-and-broad-spectrum/
date: 2026-11-11T17:16:38-05:00
modified: 2026-11-11T17:16:38-05:00
author: "HERE City National Desk"
categories: ["Health", "National"]
site: "HERE Washington DC"
attribution: "HERE Washington DC"
---

# Sunscreen Basics for SPF and Broad Spectrum

> Ultraviolet light from the sun, sunlamps and tanning beds speeds up skin aging and can cause damage that leads to skin cancer. Sunscreen is one of the simplest defenses, but only when it is chosen and used correctly. What the label means SPF, or sun protection factor, tells you how well a product shields skin

*Source: [HERE Washington DC](https://www.herewashingtondc.com/2026/11/11/sunscreen-basics-for-spf-and-broad-spectrum/) — November 11, 2026 by HERE City National Desk*

*From the HERE City National Desk*

Ultraviolet light from the sun, sunlamps and tanning beds speeds up skin aging and can cause damage that leads to skin cancer. Sunscreen is one of the simplest defenses, but only when it is chosen and used correctly.

## What the label means

SPF, or sun protection factor, tells you how well a product shields skin from sunburn. Higher numbers, up to about 50, give more sunburn protection, but the number does not mean you can stay out longer in proportion to it. An SPF 15 product does not let you stay out 15 times as long as bare skin.

Look for the words broad spectrum. These products help block both kinds of UV rays, UVA and UVB, while the SPF number mainly reflects UVB protection. A product that lacks broad spectrum coverage or falls under SPF 15 must say on its label that it only guards against sunburn and does nothing about skin cancer or early aging.

## How to apply it

Choose SPF 15 as the floor, and know that some doctors suggest SPF 30 or higher. Put it on about 15 to 30 minutes before heading outside so it has time to work. An average adult needs about an ounce, roughly a shot glass full, to cover the body evenly. Do not forget ears, the back of the neck, feet and lips, and use an SPF lip balm.

Put it on again every two hours at the latest, and sooner after swimming or heavy sweating. No sunscreen is truly waterproof. Products labeled water resistant must say how many minutes the protection lasts in water.

## Sunscreen is not the only tool

The sun is strongest from mid-morning through late afternoon, and its rays pass through clouds, windows and light clothing. They also bounce off sand, water, snow and pavement. Pair sunscreen with a wide-brimmed hat that shades the face, neck and ears, sunglasses that block UV and tightly woven clothing with long sleeves.

## Check the date

Sunscreen loses strength over time. If a bottle has no expiration date, treat it as expired three years after you bought it and replace it. When using spray products, keep away from open flames and do not smoke until the product has dried, because some sprays are flammable.