( 𝑉 𝑖 𝑉 𝑟𝑒𝑓 ) 𝑛 = ( 𝑀𝐼 𝑖 𝑀𝐼 𝑟𝑒𝑓 ) 𝑛 (6) The comparisons between the social cost of plastic pollution and the social cost of CO2 for food trays and takeaway containers made of the ith material were calculated according to Equation 7. (7) where 𝜀 𝑝𝑜𝑙𝑙𝑢𝑡𝑖𝑜𝑛 was the social cost of plastic pollution, 𝑓 𝑙𝑒𝑎𝑘𝑎𝑔𝑒 was the frequency the item leaks into the environment. Notably, Equation 7 demonstrates a dependence on article thickness.