Flip on a television anywhere across Washington state and within minutes the barrage of advertisements makes clear that the latest fight over whether to require companies to label foods containing genetically modified ingredients has turned expensive and polarizing — not to mention perplexing for many people.

On Tuesday, residents will vote on Initiative 522, which would force growers and manufacturers to disclose their use of genetically altered crops such as corn and soy, which are widely used in processed foods.

If the initiative is approved, Washington will become the first state to pass such labeling requirements. The outcome could have broad implications for the rest of America, where the issue has demanded increasing attention in recent years. Dozens of states have begun to consider legislation to label genetically modified foods, and a measure similar to I-522 failed in California last year after a bruising fight between activists and the food and industrial agriculture industry.