Most frozen green beans at the store come from large commodity farms that rely on routine spraying. Many "steamer" or seasoned versions add butter sauces, salt, or flavorings. Ours are grown without any sprays and frozen with nothing on them.
Keep frozen until ready to use. No need to thaw: steam, sauté, or roast straight from the freezer. Once thawed, use within 2–3 days.