The Commission is issuing a rule to require child-resistant packaging for naproxen preparations containing 250 mg or more of naproxen per retail package. Naproxen is marketed as an anti- inflammatory drug. It is used to treat various forms of arthritis, mild to moderate pain, and menstrual pain. The Commission has determined that child-resistant packaging is necessary to protect children under 5 years of age from serious personal injury and serious illness resulting from ingesting naproxen. The Commission takes this action under the authority of the Poison Prevention Packaging Act of 1970.