Because plastic products can persist in the environment as pollution, their impact is cumulative every year they remain. Therefore, we propose that the cost of plastic pollution (𝐶 𝑃 ) i.e., its value, can be defined as a performance-exchange constant pair of environmental lifetime and the cost of plastic pollution per mass of material per year in the environment. Accordingly, the cost of plastic pollution is realized as the product of the exchange constant (𝛼 𝐿 ) and the integrated mass over a product's environmental lifetime (Equation ), where 𝑚 is the instantaneous mass of the product from when it first entered the environment (𝑡 = 0) to when it is completely degraded (𝑡 = 𝑡 𝐿 ).