Beginning in August, New York City will require that fish served raw in restaurants be frozen before serving, according to The New York Times. For purist diners of sushi and sashimi who may take offense at the idea of their fresh catch coming from a freezer, the new food safety law is meant to ensure that bacteria and parasites don’t come with it. And, as it turns out, a number of restaurants are already freezing their fish as a safety precaution, with most customers being unaware. The new rules require restaurants to keep their fish frozen for anywhere from 15 hours to a week, depending on the temperature setting of the freezer. A number of seafood products are exempt from the rules, including shellfish and farm-raised fish. One restaurant, Sushi Zen, has been deep-freezing its fish to -83 degrees F for years to eliminate the threat of parasites and other harmful pathogens. Additionally, the majority of the fish sold in the U.S. is flash-frozen somewhere along the supply chain to maintain freshness. Raw fish served as sushi and sashimi has caused a few foodborne illness outbreaks in the U.S. in recent years. Most recently, sushi was believed to have caused at least 50 illnesses in a nine-state Salmonella outbreak. In 2012, raw tuna contaminated with Salmonella caused an outbreak that sickened more than 300 people in 26 states. The new law will go into effect in August, so the clock is ticking for any sushi aficionados who wants to dine a little more dangerously. (To sign up for a free subscription to Food Safety News, click here.)