The Honolulu Fire Department is encouraging Fourth of July celebrants to be mindful of the risks that fireworks pose in the middle of a dry season and in a densely populated city.

"The risks are inherent in the product, but because of the environment (in Honolulu) the probability is higher," said Fire Capt. Terry Seelig, the department spokesman.

Seelig noted the fire risks of summer's dry vegetation.

Beth-Ann Kozlovich of the American Lung Association of Hawai'i pointed out the health dangers of fireworks: Many people have trouble breathing when fireworks are set off in high numbers.

"It's what gets released in the combustion that causes problems for many," Kozlovich said in an e-mail. "The smoke and particulates released into the air from fireworks can really bother people with lung disease — and many who don't (have lung disease). That's the issue. Even sparklers can really bother some people."

People on O'ahu may purchase fireworks until 8 p.m. today, and are allowed to ignite them from 1 to 9 p.m.

You do not need a permit to buy novelty fireworks, such as sparklers and small fountains, and paperless firecrackers. A $25 permit from a satellite city hall is required to buy firecrackers. The permit allows a purchase of up to 5,000 firecrackers. Satellite city halls are closed today.

HFD regulations prohibit setting off fireworks on public beaches, forests or wildlife preserves; on public ways; in parks, cane fields or places of worship; within 500 feet of a hotel; within 1,000 feet of hospitals, health care and elderly care facilities, and facilities for the care of animals, including the zoo; and in school buildings or on school grounds.

They prohibit throwing fireworks from above the first floor of any building; from, at, or into a vehicle; or at a person or animal.

People are not allowed to possess or use aerial fireworks without a display permit from the fire chief.

Fireworks cannot be offered for sale by private buyers or given to minors. Parents or guardians may allow a minor to use fireworks under their supervision.

You are not allowed to transport fireworks in carry-on or checked luggage, airline cargo or mail.

You are not allowed to remove or extract pyrotechnic contents.