The modern Oreo cookie filling was developed by Nabisco’s principal food scientist, Sam Porcello, who retired from Nabisco in 1993. Porcello held five patents directly related to his work on the Oreo; he also created a range of Oreo cookies that were covered in dark chocolate and white chocolate. In the early 1990s, health concerns prompted Nabisco to replace the lard in the crème filling with partially hydrogenated vegetable oil. Oreo cookies are popular with people that have certain dietary restrictions, such as vegans, as the crème filling does not use any animal products. However, there is still a risk of cross-contamination from other dairy-containing products made in the same production areas.