Today, disposable coffee cup lids are made from PLA, PP, or PS (Figure ); which material "best" reduces environmental impact, however, is non-obvious. Comparing MIs for several environmental impact categories included in LCAs indicated that of the three materials, PP was the best. PP minimized MIs for GHG emissions and water usage (Figure ). Ironically, PP is one of the most abundant types of plastic found in marine garbage patches. Calculated value as the sum of the cost of material and the social cost of CO2 per 1000 lids expressed in 2016 $USD for PP, PS, and PLA ranged from $9.17 to $10.72 for PP, $11.61 to $16.46 for PS, and $6.99 to $11.60 for PLA (Figures ). Thus, overall, no material was much better than another. Though abridged, the result is not expected to change, given that conventional LCA impact categories trend well with GHG emissions. Lid design should account for persistence. Of the three materials, PS was optimal for environmental lifetime (Figure ). Including persistence (cost of plastic pollution) could increase the cost per 1000 lids expressed in 2016 $USD for PLA and PP to over $200 while increasing the cost for PS to ~$20. Our analyses suggest that PS may be the least impactful of the three materials on the market for disposable lids.