There’s a small window in Arizona when it’s legal to set off fireworks – but even the legal ones make public-safety workers nervous.

About 280 people on average go to emergency rooms nationwide with fireworks-related injuries in the month surrounding the July 4 holiday, according to U.S. Consumer Product Safety Commission.

The Phoenix Fire Department on Thursday held a safety briefing to demonstrate the risks of igniting legal – and illegal – fireworks.

 1. Certain types of consumer-grade fireworks are legal in Arizona until July 6, but Roman candles, which launch projectiles into the air, are illegal year-round. Pointing one in the wrong direction could result in serious bodily harm, fire inspector Dan Farren said.
2. Phoenix Fire Department blew up this tomato with a firecracker to demonstrate what could happen if one explodes in your hands. “It could blow your fingers off,” Farren said.

3. Fire inspector Steve Petrie pressed a sparkler against a glove filled with ground beef to simulate what could happen to your skin. According to a 2015 report by the U.S. Consumer Product Safety Commission, sparklers are responsible for more than 30 percent of fireworks-related injuries. Many consumer-grade sparklers burn at more than 1,200 degrees Fahrenheit.

4. Although fountain fireworks are legal in Arizona, anything that “launches into the air or explodes” is not, according to Phoenix Fire Department. Other legal types of fireworks in Arizona include ground spinners, sparklers and some novelty items, such as glow worms. They can be used legally from June 24 to July 6. After that, you could be fined $1,000.

5. Phoenix firefighters blew up a watermelon with a large firecracker – firecrackers of any size are illegal in Arizona – to demonstrate the power of consumer-grade fireworks. “They’re more powerful than you might think,” Farren said. Instead of lighting your own fireworks, Phoenix fire officials recommend watching a professional public display.