Allergen-Free Camsquare Storage Container 5.7 litre: Clear 5.7l food storage container made from virtually unbreakable polycarbonate. Purple Markings.: Designate Allergen-Free ingredients using Camsquare food storage containers. These personalised containers include easy-to-identify purple graduations and Allergen-Free imprint on the opposite side. Use with SFC6SCPP441 allergen-free purple seal lid.