The whiteness and stability of a polyolefin have been found to be improved
upon addition of a first phosphite, an arylalkyl diphosphite, and a
second phosphite selected from a second arylalkyl disphosphite or a
triarylphosphite. In addition, the addition of a triarylphosphite with an
arylalkyl disphoshite has been found to improve the hygroscopic nature
and the hydrolytic stability of the arylalkyl disphosphite.