The San Francisco Board of Supervisors unanimously approved an ordinance that will require certain grocery stores to report the use of antibiotics in raw meat and poultry. Scheduled to take effect in April 2018, the ordinance requires grocers that own or operate 25 or more stores to submit annual reports that include the purposes for which the antibiotics were used, the number of animals raised, the total volume of antibiotics administered and whether the use was “medically important.” City departments will be subject to the ordinance, which requires local authorities to “audit” their meat purchases and estimate whether and when they can transition to meat and poultry raised without the routine use of antibiotics.

Public health and environmental groups hope the measure will put pressure on the meat and grocery industries to stock products with lower levels of antibiotics. However, critics warn the ordinance could cause the price of meat in San Francisco to increase through brands pulling out of the city or passing inspection prices on to the consumers.

The law is the first of its kind to be passed in the U.S., and requires local retailers to collect annual data from suppliers on their antibiotics policies and practices. Furthermore, grocers must back up the information with evidence, such as a third-party certification, or risk fines of up to $1,000 per day, per violation.