Designing a warning label that meets the requirements of consumers, producers, and regulatory agencies is a challenging task. Such warnings must be clearly visible and must make the user aware of the consequences of improperly using the product containing the label. Once the label is designed, it must be tested. Does it attract people's attention? Do people read it? Do they understand it? A method for testing the effectiveness of a label is presented and suggestions for maintaining an unbiased test are offered.