Some studies have shown that certain plastic utensils have bisphenol A (BPA). When heated, the chemicals are released and can be consumed. BPA can have an effect on hormones when consumed, causing developmental issues, according to WebMD.
There has also been some evidence that using BPA products can lead to cancer, notes WebMD. While none of the studies have been finalized, there does seem to be a risk with BPA. Using a stainless steel straw is the safest option. The thinner straws might not contain BPA as it is used to create the stronger plastic. Cooling the beverage down is another safe option.