As the main tour group progressed through Laboratory section of the Visitors’ Center on Isla Nublar, they passed by a glass partition that was branded with a biohazard sign. Underneath the Biohazard sign, there was a disclaimer that stated that Teratogenic Substances lay beyond the door, since there were radioactive isotopes in use in that section of the laboratories. Tim Murphy was particularly excited to see the sign, as he expected that the tour would pass through. However, he was proven wrong as Ed Regis quickly claimed the sign was up for ‘legal reasons’ and assured the group that the operations were perfectly safe. Teratogenic Agents can cause birth defects and other complications to pregnant women, hence the reason for the sign.
Jurassic Park by Michael Crichton page 97-98(First Edition, Thirty Fourth printing)