Whether cardboard, plastic or metal, food packaging incorporates a wide range of chemical compounds that can leach into food.  A recent study identified over 3,000 food contact chemicals in blood samples through a bio-monitoring program.  A second study disclosed that a proportion of these chemicals are potential carcinogens with detection of the specific compounds in blood and human tissues.

Concerns arise as a result of advances in analytical technology that can detect chemicals down to picogram levels in tissues that may not be of biological significance.  Notwithstanding this caution, known carcinogenic compounds including bisphenols, styrene and phthalates should be excluded from packaging given their ability to transfer to food.

In many respects, eggshells although susceptible to cracks and leakage with mishandling representing a problem for producers, protect the egg contents from food contact chemicals in packaging.