According to the Star K, Paper Cups and Plates are acceptable for Pesach (without a KFP certification) ONLY for cold foods/drinks. For use with hot foods/drinks, a Kosher for Pesach certification is required.

Pas Yisroel during Aseres Yimei Teshuva
אלול — Guidance for Aseres Yimei Teshuva: Pas Akum, Pas Yisroel, and Rosh Hashana By Rabbi Eliezer Eidlitz Main Ideas During Aseres Yimei Teshuva, the