Every clear case promises to stay crystal clear. Only some deliver, and the difference usually comes down to three letters printed in the spec sheet: HALS. Understanding what they are tells you which clear case will still look new in a year.
What HALS Stands For
HALS means Hindered Amine Light Stabilizers. They are a family of chemical additives blended into the plastic (usually TPU or polyurethane) during manufacturing. Their job is to interrupt the chemical chain reaction that ultraviolet light starts inside clear polymers, which is the reaction that turns a fresh clear case a dull yellow-brown over time.
How HALS Fights Yellowing
When UV light hits plastic, it creates unstable molecules called free radicals that break polymer chains and produce yellow-colored compounds. HALS act as radical scavengers: they capture those free radicals and regenerate themselves, so a small amount keeps working for years. This is different from a simple UV absorber, which gets used up. A quality clear shell paired with a clear tempered glass protector keeps the whole front and back looking new.
How to Spot a HALS Case
Look for the words HALS, anti-yellowing, or anti-oxidation in the description. Cases without these additives are cheaper but tend to discolor within months, especially with sun and skin-oil exposure. Browse protective options in the cases collection.
Frequently Asked Questions
Does HALS stop yellowing forever? No additive is permanent, but HALS dramatically slows it. A HALS-treated case can stay clear for a year or more versus a few months for an untreated one.
Is HALS the same as a UV coating? No. A UV absorber blocks light and is consumed over time. HALS work continuously by neutralizing free radicals and regenerating, so they last far longer.
Do all clear cases use HALS? No. Budget cases often skip it to cut cost. Check the spec sheet for HALS or anti-yellowing language before buying.
If a clear case does not mention HALS or anti-yellowing, assume it will discolor. The additive is the single best predictor of long-term clarity.