Failure Pattern
Occurring in both static and dynamic seals exposed to atmospheres containing ozone and other air pollutants, weather and ozone cracking is marked by the appearance of many small surface cracks perpendicular to the direction of stress.

Problem Sources
Ozone attack of the polymer chains causing O-ring cracking.

Suggested Solutions
Employ O-ring elastomers that are resistant to ozone attack (see Chemical Compatibility Table, Section 6 in the Seal Design Guide).

O-RING RULE OF THUMB #12

When it is said that an elastomer is good for an application it is meant that some compounds which include that material are acceptable. Not All. For instance, some compounds of EP are good for brake fluid applications, but most are not acceptable. » Learn More