In the face of a growing national opioid epidemic, cities across the United States are beginning to rally around opening up safe injection facilities—spaces where people who inject drugs can use substances like heroin under medical supervision, Vox reports.

San Francisco is the latest city to consider opening up one of the controversial sites, following similar discussions in Philadelphia and Seattle. The centers aim to offer sterile injection equipment to slow the spread of hepatitis C virus (HCV) and HIV and to reduce overdose deaths by having trained staff on site ready to administer the opioid-reversing drug naloxone if anything goes wrong. The sites may also help link people who use drugs with substance abuse treatment upon request.

Officials in San Francisco said this week that they intend to open up such a space, potentially as soon as July. They referenced several studies showing that the harm reduction hot spots help reduce potentially fatal overdoses, related emergency care calls and some of the risky behaviors that increase the risk of HIV and hep C transmissions. The sites, which have already opened in Canada, Australia and Europe, have also helped cut back on some of the general public disorder associated with injection drug use. 

However, safe injection facilities remain highly controversial in the United States. For decades, America’s war on drugs policy has prioritized the criminalization of people who use drugs. Furthermore, harm reduction critics suggest that such facilities could encourage drug use. But many health advocates challenge that charge and argue that new solutions are needed to rein in the crisis.

San Francisco could be the first city in the country to start operating a U.S. safe injection site. Earlier this year, Philadelphia announced its intention to open up a similar site, and last year, Seattle allocated $1.3 million in the city’s budget to launch one. However, it is not clear when the sites in either of those cities would open.

Other cities considering safe injection sites include Denver; Ithaca, New York; and New York City.