A report finding hazardous chemicals in boxed macaroni and cheese may have alarmed fans of the inexpensive and convenient meal, but food safety lawyers say any litigation over the issue faces formidable challenges.

The envelope of powdered cheese flavoring in macaroni and cheese has high concentrations of phthalates, a class of chemicals that have been linked to health risks when consumed by pregnant women and young children, according to test results issued in June by a group called the Coalition for Safer Food Processing and Packaging. Phthalates are not added as an ingredient but are believed to migrate into food through contact with plastic processing equipment and packaging.