Chiron has been involved in the preparation of steroid and triterpanoid (hopane) reference materials used in the petroleum industry for over 30 years. These compounds are found in petroleum and sediments. Hopanes are in fact the second largest group of natural products on earth, surpassed only by cellulose. This type of compound changes its chemical structure over time and maturation. They have traditionally been used in petroleum exploration, but have lately been increasingly used for forensic analysis, for example in the investigation of oil spills. Chiron works with major oil companies, institutions, private laboratories, universities and hospitals in this area, and is currently the only producer of a large range of oil exploration reference materials in the world.