In the wake of a sharp rise in the number of young children accidentally eating melatonin supplements, an industry group has called for tougher safety guidelines for packaging and labeling the sleep-aid supplements. Companies have 18 to 24 months to voluntarily add child-deterrent packaging and improve warning language on the labels of over-the-counter melatonin products, the Council for Responsible Nutrition (CRN) said Monday in news release announcing the more stringent guidelines.