I'd suggest searching for "EPDM" rubber bands. These are a higher
quality material that is claims resistance to ultraviolet light,
ozone, weather and aging.

Ken Christ

[ EPDM File Bands are non-latex rubber bands made from a type of
[ synthetic rubber called EPDM (Ethylene Propylene Diene Monomer). Ref.
[ https://www.rubberband.com/product-category/consumer-products/xtreme-file-bands-epdm-non-latex/ 
[ -- Robbie