PP products have better elasticity to allow them to rebound faster after bending without leaving much bending marks. PLA products are more brittle than PP, so it is easier to leave bending marks. The density of PP product is lower than that of water, so it will float on the water surface in a cup, while the density of PLA product is higher than that of water, so it will sink into the bottom of the cup. Generally, PP products can withstand a heat up to 248 ℉, so they are not easy to soften and bend when placed in 212 ℉ hot water, while PLA straws produced by GoodBioPak can withstand a heat up to 176 ℉, so the straws are easy to deform and bend when placed in 212 ℉ water. PP product is artificially synthesized by chemical means, so it will give off a pungent smell after burning, while PLA product is made of plant starch such as corn, so it will develop a burnt edge and give off a caramel smell after burning.