Heroin is a semi-synthetic opioid manufactured from morphine. This drug is originally extracted from the seed of opium poppy plant, and uses as both painkiller and recreational drug. It is illegal to manufacture and to sell in the U.S., but in some countries, it is legally prescribed drug.

Cotinine is a metabolic of nicotine, used to measure the grade of tobacco smoking. According to National Survey On Drug Use 2007, overall 68 million people abuse tobacco, and more than 3.5 million teens abuse tobacco between 12-17 years.

Many schools are using student drug testing as part of their regular activities. According to Ring Walt survey May 2008, a 16.5% of U.S. school districts have adopted/implemented student random illicit drug testing programs.