Heat the oil in a deep fryer or electric skillet to 375 degrees F (190 degrees C).
Combine the green beans and water in a saucepan. Cover and bring to a boil. Cook until the beans are bright green, about 4 minutes. Drain and transfer to a bowl. Cover with cold water and set aside.
In one bowl, whisk the egg and milk together. In a separate bowl, mix together the bread crumbs, chili powder, garlic powder, and onion powder. Drain the green beans and toss with flour to coat, shaking off the excess. Dip the beans into the egg mixture and then into the bread crumbs, coating thoroughly.
Fry beans in batches so they are not touching. Cook until golden brown and crispy, about 2 minutes. Drain on paper towels.