Control of the cellular environment is a principal attribute of in vitro cell cultures. Unintentional exposure to environmental compounds can adversely affect cultures and, therefore, experimental results. Estrogenic compounds arising from common plastic ware have been found during cell culture. One such compound, the environmental endocrine disrupting chemical bisphenol A, can bind to estrogen receptors and effect cellular changes. We monitored bisphenol A concentrations in culture dishes from six different manufacturers under typical cell-culture conditions. With the use of a gas chromatography mass–spectrometry assay we determined that bisphenol A contamination from the culture dishes did not occur. These findings will allow scientists concerned about possible effects of bisphenol A on their culture systems to choose appropriate plastic ware.