Disposable food containers are usually made of #5 plastic (Polypropylene aka PP) which is relatively hard and heat resistant making it suitable for food. It really has great properties.

But sadly, only about 1% of PP is recycled  globally because there is very low demand for this kind of post-consumer plastic in the 2nd hand market. 

Added to that, these containers are often the source of food contamination in the recycling system because they are difficult to clean when oily.

For all these reasons, above we recommend putting such containers in the trash instead of using up soap and water to clean them for the recycling bin.