Allergen-Free Measuring Jug, 4 litre: Allergen-free measuring jug, 4 litre capacity. Purple colour.: Keeping separate Allergen-Free, colour coded measuring cups in your kitchen can reduce the risk of cross-contact and accidental exposure to allergens during the preparation process. Externally marked purple graduations and Allergen-Free logo are imprinted in Allergen purple for easy identification.