Hydrogen Sulphide: Criminal investigation into case of six firefighters injured and two workers dead in industrial accident

Two people have died in connection with a workplace accident in southern Sweden. Toxic gas was formed during a cleaning of a tank that was used for recycling and two men collapsed from respiratory problems.

In connection with the rescue effort, six firefighters were also injured and had to be taken to hospital.

TEXT ORIGINALLY PUBLISHED ON WEDNESDAY JUNE 21. Below the initial text are updates made on June 22.  

The accident occurred on Tuesday morning, local time. 

The two dead workers are both men in their 40s.

"It is a terribly tragic event. Three rescue services arrived on site first and started life saving efforts", says Emma Nordwall, federal director of northwestern Scania's rescue service.

It was just after seven o'clock that the police and emergency services were alerted to the company Omni Polymers in the city of Ängelholm after a call to 112 that two people had collapsed inside a tank.

"It was in connection with the cleaning of tanks that this (incident) has happened. Sludge products and putrid gas has formed, including hydrogen sulphide in a concentrated form", says Patric Fors, information officer at the police department in the Swedish Region South 

The men were taken to hospital with life-threatening injuries but their lives could not be saved, as reported by Swedish Television, SVT.se.

Authorities had recently found safety issue in the plant

Only days before the accident occured, the Swedish Work Environment Agency was on site for an inspection. SVT.se has been privy to the inspection results, which allegedly pointed out several shortcomings.

One of the documents concerns  "Risk assessment of chemical risk sources and documentation of the results". The authority writes in the documentation that the company could not "prove or rule out that the air in the production hall contained substances at levels hazardous to health".

According to the Norwegian Poisons Information Centre, hydrogen sulphide can block the breathing function. Inhalation can quickly lead to unconsciousness, respiratory arrest and cardiac arrhythmias. Exposure to the gas carries a high risk of death. It is unclear how high the concentrations were in this case.

"We did a risk assessment of the gas levels and our staff had breathing masks. But the levels were higher than we thought. Then they had to back off, but several of the staff started to feel bad, says operations manager Ola Morin.

 A total of six firefighters were taken to hospital for observation.

"The four firefighter receiving medical care in Ängelholm are doing well. So are also the other two (firefighters) who were taken to the Helsingborg infirmary. We provide crisis support to our employees, says Lars Scotte, rescue manager at the Höganäs rescue service.

The police will now carry out a technical investigation. The incident is being investigated as a criminal breach of the national workplace safety regulations and also as a case of criminal negligence causing the death of another. The investigation is led by prosecutors at the National Unit for Environment and Work Environment Cases.

UPDATED JUNE 22:

On Thursday, HazMat personnel wearing chemical suits and respirators began the cleanup of the Omni Polymer plastic recycling factory in Ängelholm, Sweden. 

During Tuesday, two male industrial workers died in an occupational accident at the site, after reportedly inhaling hydrogen sulphide gas. 

"... we will help the police by going in and collecting samples from the tank (where the accident occurred)  and attempt to make it gas-free", says Leif Hylander, a national expert on dangerous substances.

The two men in their 40s died after falling about five meters into a tank that contained the toxic and explosive gas hydrogen sulphide, reports Swedish evening newspaper Aftonbladet.se.

A special rescue force from the Fire & Rescue service at Höganäs used ropes and other special equipment to extricate the two men from the bottom of the tank. 

Inhaled the gas despite wearing breathing protection

Although the rescue personnel were wearing breathing protection, it is suspected that they had still inhaled sufficient amounts of the gas to cause injuries. Six people from the rescue service team, were therefore taken to hospital for a check-up.

(Editorial Note: It is not clear exactly what type of breathing protection the fire service members were wearing)

During Wednesday, personnel from the national chemical unit arrived. In a first step, they would take samples in the affected tank:

"It will be difficult, because initially this work will be carried out in a chemical suit and using breathing apparatus. And it's hot outside, so the guys and girls who do this will have a tough task", says Leif Hylander, retired rescue manager and expert on dangerous substances. 

When the personnel from the chemical unit have taken samples, they will measure gas concentrations and then finally attempt to made the factory premises gas-free. After this,  the actual cleanup work can begin.

The work to clean up the site will be done by a specialized sanitation team specialized in dealing with hazardous materials. 

" We are talking upwards of 200 cubic meters of water and biological mass. It will be sucked out, and initially it must be put in holding tanks . Afterwards, it can be sent to the treatment plant", says Leif Hylander.

Previously criticized by the Swedish Work Environment Agency

He states that the tanks at the company consist of 40-foot containers assembled into a tank system of six to eight tanks. Hylander does not want to speculate on what happened on Tuesday:

"I am not fully aware of what exactly, but somehow, something has gone wrong. It happens at some point every year that people enter confined spaces where they shouldn't enter... sometimes they don't have measuring equipment or do a proper risk analysis before they go in. The environment can be life-threatening in tanks like this, says Leif Hylander. (Editorial note: This sentence was loosely interpreted from Swedish) 

The Swedish Work Environment Authority carried out an inspection at the company as recently as June 15, and criticized several conditions. However Ulrika Scholander, unit manager at the inspection department, says that the discovered deficiencies were probably not behind the accident.

The Norwegian Work Environment Authority will shortly send an inspector to the company to investigate how the accident could occur:

"These types of accidents are usually quite complex investigations. We want to talk to everyone involved, take in all the documentation about what their (safety) routines are.... It is very difficult to speculate whether it will take a month or two months", says Scholander.

The business idea of the affected company Omni Polymers is to recycle used plastics. The company writes on its website that it uses second hand household packaging to produce a granulate that "can replace new plastic as a raw material in new products".

Photo Credit:

Aerial view of the city of Ängelholm, Sweden. Wikipedia Commons License.

Photo by Pär-Martin Hedberg - Riksantikvarieämbetet på denna plats (Bjäre Ängelholm_HIO4533.JPG), CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=77844480