Mifegyne was subsequently approved in Great Britain on July 1, 1991,  and in Sweden in September 1992,  but until his retirement in late April 1994, Hoechst AG chairman Wolfgang Hilger, a devout Roman Catholic , blocked any further expansion in availability.   On May 16, 1994, Roussel-Uclaf announced it was donating without remuneration all rights for medical uses of mifepristone in the United States to the Population Council ,  which subsequently licensed mifepristone to Danco Laboratories , a new single-product company immune to antiabortion boycotts, which won FDA approval as Mifeprex on September 28, 2000. 
The increasing demand for ready-to-eat fresh food products has led to challenges for food distributors regarding the safety and quality of their foods. Artificial preservatives meet some of these challenges by preserving freshness for longer periods of time, but these preservatives can cause negative side-effects as well. Sodium nitrite is a preservative used in lunch meats, hams , sausages , hot dogs , and bacon to prevent botulism . It serves the important function of controlling the bacteria that cause botulism , but sodium nitrite can react with proteins , or during cooking at high heats, to form carcinogenic N-nitrosamines .  [ unreliable medical source? ] It has also been linked to cancer in lab animals.  The commonly used sodium benzoate has been found to extend the shelf life of bottled tomato paste to 40 weeks without loss of quality.  However, it can form the carcinogen benzene when combined with vitamin C . [ citation needed ] Many food manufacturers have reformed their products to eliminate this combination, but a risk still exists.  Consumption of sodium benzoate may also cause hyperactivity . For over 30 years, there has been a debate about whether or not preservatives and other food additives can cause hyperactivity . Studies have found that there may be increases in hyperactivity amongst children who consume artificial colorings and benzoate preservatives and who are already genetically predisposed to hyperactivity, but these studies were not entirely conclusive. Hyperactivity only increased moderately, and it was not determined if the preservatives, colorings, or a combination of the two were responsible for the increase.