UL 157 is a test method specification from Underwriters Laboratories (UL) for qualifying rubber products – similar to how ASTM D395 specifies compression set testing methods. However, UL 157 itself is not a listing standard.
Apple Rubber’s compounds are listed under JMLU2 for Seals and Gaskets. JMLU2 certification uses UL-157 test methods to verify compounds meet specific end-use requirements. During UL audits, auditors verify JMLU2 certification, not UL 157 compliance.
JMLU2 End-Use Codes
When requesting UL-listed compounds, specify the JMLU2 end-use code for your application. Below are the standard end-use codes for JMLU2:
Material selection must match its specific end-use. For example, while EPDM rubber suits laundry detergent applications, it would fail in gasoline environments.
Listing Example
30VT7AP is a high-fluorine FKM compound that offers enhanced chemical resistance and reduced ethanol swell. It’s JMLU2 listed for codes B, C, D, F, G, H, J, and certified under UL50E and UL 87 (A, B, C). UL 87A covers E85 blends, while UL 87B covers 100% biodiesel fuels.
Apple Rubber maintains many JMLU2-listed compounds and pre-molded o-rings with proper UL audit labeling. Contact our polymer chemists for specific listing information or engineering support for your next application.