Hawaii Kilauea Volcano: Beware of New Threat From Toxic 'Lava Haze,' Authorities Warn

As Hawaii's Kīlauea volcano continues to erupt, lava flows have reached the Pacific Ocean, prompting local authorities to issue warnings of a potentially deadly new hazard.

Hawaii County's Civil Defense (HCCD) agency published bulletins on Sunday asking residents living to the east of the summit to beware of "laze"—a combination of toxic hydrochloric acid fumes, steam and fine volcanic glass-like particles, which is formed when hot lava hits the ocean.

On Saturday and Sunday, two separate streams of lava ran into the sea, according to the U.S. Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO), severing Highway 137, which runs along the south east coast of Hawaii's Big Island. Sections of road in the vicinity of the lava flows and the local MacKenzie State Park have now been closed as a precaution.

Even small quantities of laze—a term formed by mixing the words "lava" and "haze"—can cause damage to the lungs and irritate the skin and eyes. In 2000, laze caused the deaths of two people in Hawaii, the USGS said.

"Be aware of the laze hazard and stay away from any ocean plume," the HCCD warned in a bulletin. "Laze plume travels with the wind and can change direction without warning. Health risks are present both landside and on the water. The U.S. Coast Guard is actively monitoring the area," the agency said. "Only permitted tour boats are allowed in the area."

Kīlauea—which rises 4,190 feet above Hawaii’s Big Island, making up around 14 percent of its total area—is one of the world’s most active volcanoes. It has been erupting—in some form—on a continuous basis since 1983.

The latest spike in activity began on May 3, when lava and toxic sulfuric acid plumes began pouring and spattering out of newly opened fissures along the volcano's East Rift Zone. This activity has been accompanied by a series of minor earthquakes.

Over the past weeks Kīlauea has also spewed out large volcanic rocks from its summit crater, as well as large amounts of ash. In fact, one powerful eruption on Thursday ejected ash around 30,000 feet into the air, prompting warnings for those in the areas where it may fall to stay indoors.

The eruptions have also created a phenomenon known as "vog"—a combination of water, carbon dioxide, sulfur dioxide, dust and fine particles, which can cause irritation to the lungs, especially in people who suffer from respiratory problems.

According to Reuters, local authorities reported the first known serious injury linked to the latest round of eruptions on Saturday after a man was hit in the leg by lava splatter while standing on the third-floor balcony of his home. The impact of the lava shattered his leg from the shin to the foot.

So far, the lava flows have destroyed a number of homes and other structures, the Associated Press reports, and has ignited several fires. Thousands of residents who live to the east of the summit have fled or been evacuated by authorities. If the volcanic activity continues to this extent, Hawaiian officials are planning for more evacuations. However, they stress that most of the Big Island and the rest of the state remains largely unaffected by the latest events.