The chemical compatibility of LDPE and HDPE on this chart is tested at 20°C: and 50°C: for 7 days and 30 days (if applicable) with constant exposure. LDPE & HDPE resistance listed by chemical. 1.4-dioxane. LDPE / HDPE at 20°C: little or no damage after 30 days. LDPE at 50°C: shows some effect after 7 days.