(NewsNation) — The House of Representatives has voted to reclassify permanently fentanyl-related substances, or fentanyl analogs, as Schedule I drugs.

The bill must still go to the Senate, but if passed there, it would make permanent harsh criminal penalties for those distributing the drugs. A number of Democratic lawmakers joined nearly all of the Republican members of the House in a bipartisan show of approval. If it passes the Senate, it will make permanent a temporary measure that would have expired in 2024.

The government classifies drugs based on their medical use and the potential for addiction. Schedule I drugs are considered to have a high potential for addiction but no accepted medical use. The class includes drugs such as heroin, LSD, ecstasy and marijuana (though the Biden administration has taken steps to reclassify marijuana at a lower level).

The way a drug is classified can guide criminal prosecution if a suspect is found to have distributed it illegally. But it can also affect how easily available it is to researchers and scientists.

A number of scientists and doctors urged the Biden administration to hold off on reclassifying fentanyl-related substances, saying the move could hinder research into antidotes for overdoses. Researchers who want to work with Schedule I drugs have to go through an extensive application process and meet certain security requirements before being allowed to work with the drug. It’s also harder for them to get grant money to conduct those studies.

The legislation does continue to classify fentanyl itself, which does have medicinal uses, as a Schedule II drug. Schedule II drugs are those with a high potential for abuse, but which also have legitimate medical uses. Many strong painkillers are in that class, as well as medications such as Adderall used to treat ADHD.

There are also provisions to allow researchers working with fentanyl analogs in an effort to find antidotes to continue working with the substances. But some Democrats raised concerns that it does not include a way to delist any fentanyl analogs that may be found to be beneficial in the future.

Some opponents of the bill view it as an effort to use criminal penalties to address a public health problem, though the Biden administration supported the bill.

Those who supported reclassifying fentanyl-related drugs point to the rising rate of overdoses, and they say that if those substances are not permanently classified as Schedule I, it will hinder the ability of law enforcement to seize and prosecute those who distribute them illegally.

The companion legislation in the Senate has so far gained only support from Republicans in the upper chamber.