create a new cart column to hold the recycle fee. for the sake of example, call the column "RecycleFee"
then in the cart object, add a new calculation as:
[RecycleFee] * [Quantity]
On the charges tab, add a new charge.
set the trigger to Total number of items in cart greater than 0
for the calculation use:
"Based on column Subtotal"
Subtotal of Column "RecycleTotal" "Plus" "0"