The USDA Complete Guide to Home Canning states that green beans
and wax beans can be processed in a hot water bath or hot pack
method using a pressure canner. Refer to Guide 4 of this USDA
canning guide, it is titled "Guide 4 Selecting, Preparing, and
Canning Vegetables and Vegetable Products". The guide (all parts)
are available as download in a PDF file format.