PA rating
Also called: Protection Grade of UVA, PA+, PA++++
PA rating is a UVA protection label system, developed in Japan, that uses plus signs to communicate UVA protection strength. More plus signs mean higher measured UVA protection.
At a glance
- PA is about UVA protection, not UVB sunburn protection.
- PA ratings are based on persistent pigment darkening values.
- PA++++ usually indicates the highest category in the modern four-level PA system.
On this page
The short answer
PA is a UVA label system. Japan's PA system uses persistent pigment darkening values and groups them into plus-sign categories: PA+, PA++, PA+++, and PA++++[1].
In normal language, more plus signs means stronger UVA protection in that system.
How PA differs from SPF
SPF is mostly about UVB-driven sunburn. PA is about UVA, the longer-wavelength UV range linked with tanning, visible ageing, and skin cancer risk[2].
That means SPF 50 and PA++++ are not competing claims. They answer different label questions.
What to do with this
If a sunscreen uses PA ratings, treat PA++++ as a good sign for UVA protection. If it does not use PA, do not panic. On US-style labels, broad spectrum is the simpler UVA-plus-UVB phrase to look for.
Keep reading
Common questions
Is PA the same as SPF?
No. SPF mainly relates to UVB sunburn protection. PA is a UVA protection grade.
Is PA++++ always better?
It signals a higher UVA protection category, but the sunscreen still needs to suit your skin and be applied generously enough.
Citations
- Japan PA System for UVA Protection Revised - RatzillaCosme summary of Japan PA system revision
- Skin Cancer Foundation: UV Radiation - Skin Cancer Foundation