Six gas-related fatalities during July 2007

Salak is a stratovolcano near the W end of Java (figure 1). Historical records indicate the last eruption occurred in 1938, and the volcano remains in repose; this report discusses gas-related fatalities. The last section of this report reviews gas exposure limits, gas-mask filters, and monitoring devices to enhance understanding of two sulfurous volcanic gases (SO₂ and H₂S).

Figure 1. Satellite imagery from Google Earth showing Salak (center, ~60 km SSW of Jakarta) and other volcanoes of western Java. Courtesy of Google Earth.

According to news articles, sulfur-gas poisoning from one of Salak's fume-filled craters was suspected in the deaths of six teenagers on 7 July 2007. The victims, who were between the ages of 14 and 16, were part of a group of about 50 students camping on the volcano for the weekend. The bodies were found with blood and foam on their mouths and noses. According to a Reuters report of 9 July 2007, police officer Thomas Alexander reported that "one of the students was found dead with foam on his mouth, a strong indicator of sulfur poisoning." Several more poisoned students were taken to a nearby hospital for treatment.

Deadly gases. A data sheet on SO₂, a common and potentially hazardous sulfurous gas found at volcanoes appears on the Center for Disease Control website (NIOSH, 2007). The gas's density is 2.26 times heavier than air of the same temperature. (In other words, when near the ambient air temperature, SO₂ gas will generally tend to descend into low-lying places such as closed craters, lava tubes, etc.) The NIOSH recommended exposure limit for a 40 hour work-week composed of up to10-hour days is 2 ppm. Their stated recommended exposure limit for short-term (15-minute) exposure is 13 ppm.

These guidelines apply only to healthy adults, and exclude the effects of multiple gases, strong physical exertion, etc. Another hazardous sulfurous gas emitted by volcanoes is H₂S. It has a density of 1.2 times that of air and a recommended exposure limit that is a more stringent (NIOSH ceiling) value that should not be exceeded: 10 ppm for 10 minutes. But, this gas is thought to quickly react to form SO₂ in many circumstances. The NIOSH website also discusses appropriate filters for gas masks. Small, portable, digital monitors now exist for many gases; some will operate as remote sensors with dedicated telemetry.

Reference. NIOSH, 2007, NIOSH Pocket Guide to Chemical Hazards, Sulfur dioxide: US Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health (URL: http://www.cdc.gov/niosh/npg/npgd0575.html).

Information Contacts: Reuters (URL: http://www.reuters.com/); Asia-Pacific News (URL: http://www.asiapacificnews.com/); Associated Press (URL: http://www.ap.org/); Deutsche-Presse Agentur (URL: http://www.dpa.de/).

Information is preliminary and subject to change. All times are local (unless otherwise noted)

September 2007 (BGVN 32:09) Cite this Report

Six gas-related fatalities during July 2007

Salak is a stratovolcano near the W end of Java (figure 1). Historical records indicate the last eruption occurred in 1938, and the volcano remains in repose; this report discusses gas-related fatalities. The last section of this report reviews gas exposure limits, gas-mask filters, and monitoring devices to enhance understanding of two sulfurous volcanic gases (SO₂ and H₂S).

Figure 1. Satellite imagery from Google Earth showing Salak (center, ~60 km SSW of Jakarta) and other volcanoes of western Java. Courtesy of Google Earth.

According to news articles, sulfur-gas poisoning from one of Salak's fume-filled craters was suspected in the deaths of six teenagers on 7 July 2007. The victims, who were between the ages of 14 and 16, were part of a group of about 50 students camping on the volcano for the weekend. The bodies were found with blood and foam on their mouths and noses. According to a Reuters report of 9 July 2007, police officer Thomas Alexander reported that "one of the students was found dead with foam on his mouth, a strong indicator of sulfur poisoning." Several more poisoned students were taken to a nearby hospital for treatment.

Deadly gases. A data sheet on SO₂, a common and potentially hazardous sulfurous gas found at volcanoes appears on the Center for Disease Control website (NIOSH, 2007). The gas's density is 2.26 times heavier than air of the same temperature. (In other words, when near the ambient air temperature, SO₂ gas will generally tend to descend into low-lying places such as closed craters, lava tubes, etc.) The NIOSH recommended exposure limit for a 40 hour work-week composed of up to10-hour days is 2 ppm. Their stated recommended exposure limit for short-term (15-minute) exposure is 13 ppm.

These guidelines apply only to healthy adults, and exclude the effects of multiple gases, strong physical exertion, etc. Another hazardous sulfurous gas emitted by volcanoes is H₂S. It has a density of 1.2 times that of air and a recommended exposure limit that is a more stringent (NIOSH ceiling) value that should not be exceeded: 10 ppm for 10 minutes. But, this gas is thought to quickly react to form SO₂ in many circumstances. The NIOSH website also discusses appropriate filters for gas masks. Small, portable, digital monitors now exist for many gases; some will operate as remote sensors with dedicated telemetry.

Reference. NIOSH, 2007, NIOSH Pocket Guide to Chemical Hazards, Sulfur dioxide: US Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health (URL: http://www.cdc.gov/niosh/npg/npgd0575.html).

Information Contacts: Reuters (URL: http://www.reuters.com/); Asia-Pacific News (URL: http://www.asiapacificnews.com/); Associated Press (URL: http://www.ap.org/); Deutsche-Presse Agentur (URL: http://www.dpa.de/).