Why miners in Indonesia risk their lives to get sulfur from inside an active volcano

• In Indonesia's Ijen volcano, hundreds of miners risk respiratory illness and physical harm.
• They're mining sulfur, an essential ingredient in sugar, detergent, and gunpowder.

In East Java, Indonesia, hundreds of miners face deadly smoke to mine sulfur, or "devil's gold." They risk respiratory illness and death to haul 200-pound loads of sulfur up crater walls. So, why do they do it? We head to Ijen volcano to find out.

Hundreds of miners work inside the Ijen volcano, an active volcano in Indonesia.

Miners inside of the Ijen volcano.      Rizky Zulfi Anwar and Aan Herlambang/Insider

The Ijen volcano complex is a group of volcanoes located on the eastern end of Java.

The Ijen volcano complex, located in eastern Java.      Rizky Zulfi Anwar and Aan Herlambang/Insider

Throughout their workdays, the miners battle toxic fumes.

A miner at Ijen volcano.      Rizky Zulfi Anwar and Aan Herlambang/Insider

They're mining sulfur, which locals call "devil's gold" because of its two colors.

Sulfur, nicknamed "devil's gold."      Rizky Zulfi Anwar and Aan Herlambang/Insider

Miners carry up to 200 pounds of sulfur on their backs, up and down steep cliffs. It's common for their shoulders to swell or develop pimples.

A sulfur miner hikes up a steep cliff.      Rizky Zulfi Anwar and Aan Herlambang/Insider

Sulfur is a common household ingredient, used in everything from matches to batteries to sugar. It's an essential ingredient in rubber products and winemaking, and it's used in fireworks and gunpowder.

Sulfur is a common household ingredient.      Rizky Zulfi Anwar and Aan Herlambang/Insider

Despite its risks, sulfur mining is an attractive job in this remote part of Indonesia. It pays well compared to the island's other trades: sulfur miners earn about $12 to $17 a day.

Sulfur mining pays better than other jobs on the island.      Rizky Zulfi Anwar and Aan Herlambang/Insider

At the start of each day, Mistar, a sulfur miner, travels to the crater on a bicycle until the road ends. Then he hikes 2 miles to the ridge of the volcano.

Mistar, a sulfur miner, travels to the crater on foot.      Rizky Zulfi Anwar and Aan Herlambang/Insider

He takes only his basket and crowbar down into the 1,000-foot-deep crater.

Mistar takes his equipment down a steep hike into the crater.      Rizky Zulfi Anwar and Aan Herlambang/Insider

The volcano has an extreme environment, where the air can reach over 100 degrees Fahrenheit.

The Ijen volcano creates an extreme environment.      Rizky Zulfi Anwar and Aan Herlambang/Insider

Mistar works near one of the world's most toxic volcano lakes. The acid content in the lake is like battery acid, and if it comes into contact with workers' mouths, their teeth could fall out. If ingested, it is deadly.

A toxic volcano lake.      Rizky Zulfi Anwar and Aan Herlambang/Insider

"The smell of sulfur smoke is very strong," Mistar said. "It smells sour, sometimes like the smell of eggs being fried. But if it gets into your nose or mouth, it will suffocate us. It makes us cough."

Miners protect themselves from the sulfur smoke with masks.      Rizky Zulfi Anwar and Aan Herlambang/Insider

While mining company PT Candi Ngrimbi owns the license to run the mine, the miners here are contractors, so they have to pay for their own gear. Many of them cannot afford gas masks, so they use handkerchiefs or towels dipped in water to keep the sulfur powder from sticking.

Miners pay for their own gear.      Rizky Zulfi Anwar and Aan Herlambang/Insider

When the hot smoke hits the cooler air outside, it condenses into a liquid and drips off the pipe.

Liquid sulfur drips off of a pipe before solidifying.      Rizky Zulfi Anwar and Aan Herlambang/Insider

As the liquid cools and solidifies, it turns yellow. Then the miners can begin chipping off blocks of the sulfur.

Miners chip away at the yellow solid sulfur.      Rizky Zulfi Anwar and Aan Herlambang/Insider

Miners use their bare hands to move these blocks, even though frequently touching solid sulfur can cause rashes and blisters.

Touching solid sulfur can cause rashes.      Rizky Zulfi Anwar and Aan Herlambang/Insider

Once he fills his baskets, Mistar hoists them onto his shoulders to hike back. But it is not a light load: Mistar weighs 132 pounds, and the maximum weight he can carry is about 154 pounds.

Mistar carries baskets of sulfur weighing over 150 pounds.      Rizky Zulfi Anwar and Aan Herlambang/Insider

Some of the younger miners can carry up to 200 pounds in one load. They have to haul it up the steep walls of the crater.

Baskets of sulfur weighing over 150 pounds.      Rizky Zulfi Anwar and Aan Herlambang/Insider

Once he reaches the rim of the crater, Mistar can transfer the sulfur to his trolley and begin the trip back home.

Mistar makes this trip twice a day.      Rizky Zulfi Anwar and Aan Herlambang/Insider

At the factory, which is owned by PT Candi Ngrimbi, workers boil the sulfur and run it through a series of filters. They have to remove any contaminants, like sand or dirt.

Liquid sulfur goes through a series of filters.      Rizky Zulfi Anwar and Aan Herlambang/Insider

Then they pour it out onto the factory floor to cool.

Liquid sulfur cools on the factory floor.      Rizky Zulfi Anwar and Aan Herlambang/Insider

About 98% of the world's sulfur comes from the oil and gas industry, and oil companies are required by law to process it safely. Today, the sulfur industry from oil and gas is worth almost $13 billion and is expected to keep growing.

About 98% of world's sulfur comes from the oil and gas industry.      Rizky Zulfi Anwar and Aan Herlambang/Insider

This has made natural mines in volcanoes virtually unnecessary, especially since mined sulfur is not as pure as the sulfur that is a byproduct of refining.

Mined sulfur is not as pure as sulfur from refining.      Rizky Zulfi Anwar and Aan Herlambang/Insider

Ijen is one of the only places left in the world where people still mine sulfur this way, despite the danger. It's cheaper and easier for the mining company to get sulfur from Ijen, and mining pays more than other jobs on the island, like farming.

Mining pays more than other jobs on the island.      Rizky Zulfi Anwar and Aan Herlambang/Insider

Another possible reason the mine is still open is tourism.

A tourist at Ijen volcano.      Rizky Zulfi Anwar and Aan Herlambang/Insider

At night, visitors flock here to see the blue flames from the sulfur gas.

Blue flames from sulfur gas.      Rizky Zulfi Anwar and Aan Herlambang/Insider

During the day, tourists hike up to take in the vistas, watching the miners work.

Tourists at Ijen volcano.      Rizky Zulfi Anwar and Aan Herlambang/Insider

Working conditions here are so dangerous, many miners don't live past 50 years old.

Many miners don't live past 50.      Rizky Zulfi Anwar and Aan Herlambang/Insider