Is it Safe to Wash Plastic Bottles and Dishes in the Dishwasher? 02/1/2010 By: The Soft Landing

from www.thesoftlanding.com

Have you ever wondered if it's okay to wash plastic food containers in the dishwasher, even if they are BPA-free? That's a great question that requires a two-part answer, because not all plastic containers the same . . .

Most Reusable Bottles and Dishes are Dishwasher Safe
Many plastic containers are specifically intended for reuse and are usually clearly marked. The dishes in this category come from two main categories:

Heavy duty everyday reusables (dishware, utensils, baby bottles, sippy cups, etc.) are dishwasher safe and will withstand heat and detergents for many years. Some examples would be Frostware and Preserve Everyday Tableware

Take and toss style reusables are dishwasher safe but don't stand up well in the long run, so keep an eye on them and recycle them when they begin to warp. Some examples would be Nuby Wash or Toss and Gladware Food Storage

Some Food Containers from Grocery Stores are Not Dishwasher Safe
Most yogurt, cream cheese or peanut butter containers are made from polypropylene (#5) which is great in regard to the absence of toxic chemicals. But many are made with very thin plastic walls that just won't hold up when exposed to dishwasher heat and detergents. You'll have to be the judge: if the plastic container is too flimsy and ends up warped, it’s probably not meant to be reused.
Also be careful to check your take out containers, as most are made from a firm polystyrene plastic (#6) that looks and feels an awful lot like polypropylene. You'll never want to reuse these containers and you should even consider using your own on-the-go containers instead. An easy way to check for polystyrene is to look for a lack flexibility in the container. Polypropylene will be slightly cloudy and squeezable.

Don't Forget to Wash Them on the Top Rack
Always place plastic dishes on the top rack to reduce heat exposure and hand wash large dishes that won't fit up top. And while we're on the topic of heat and plastics, we don't recommend microwaving plastic at all either.