For the past five years, Woodbridge has had an active program for testing cellular plastics for dynamic response. Specifically, we have evaluated these materials under dynamic impact and recorded their response via force deflection curves. To date, we conducted several thousand tests. In the past, we looked at the effects of the impactor shape and velocity on these curves. We thought a study of sample thickness vs. impactor shape and some initial test temperature effects would be in order, particularly with the increased use of these materials in the interior of the vehicle.