Phthalates, plastic-softening chemicals used in medical tubing and children’s toys, are at the center of a contentious debate, with enviros and a number of health experts arguing that the chemicals may cause serious health problems for humans. A panel of scientists led by former Surgeon General C. Everett Koop released a report in June that claimed the chemicals were safe for humans. But Health Care Without Harm, an international coalition of 180 organizations of health workers, advocacy groups, and enviros, has issued its own report that sharply criticizes the Koop panel’s findings, saying the panel omitted significant scientific work and misrepresented data from some studies. The safety of phthalates is also being investigated by the Food and Drug Administration, the National Institutes of Health, and the National Academy of Sciences.