The Risk Management Tool Box Blog

The Australian Transport Safety Bureau (ATSB) is urging all maritime workers and boat owners to watch a short online safety video that features an accident involving a crew member on board a ship who was tragically killed by an explosion while cutting a used 200 litre drum with an angle grinder.

The ATSB has investigated several accidents involving "hot-work" cutting of used fuel drums in the marine industry.

In all cases, the  accidents could have been prevented if the workers had just given some time to think about the hazards involved and followed proper "hot-work" procedures.

The video provides a powerful reminder to all seafarers of the need to take make sure that hazards involved in "hot-work" are appropriately managed.

To view the video, click this link.

The air we breathe contains about 21 per cent oxygen.

But even a very small increase in the oxygen level in the air -  to just 24 per cent - can create a dangerous situation.

At 24 per cent concentration of oxygen in air, it becomes easier to start a fire, which will then burn hotter and more fiercely than in normal air.

Under such circumstance, it may be almost impossible to put the fire out.

Oxygen is also a hazard because it is very reactive.

Pure oxygen, at high pressure - such as from a cylinder - can react violently with common materials, such as oil and grease. Other materials may catch fire spontaneously.

Nearly all materials, including textiles, rubber and even metals, will burn vigorously in oxygen.

A leaking valve or hose in a poorly ventilated room or confined space can quickly increase the oxygen concentration to a dangerous level.

In response to the hazard posed by excess levels of oxygen, the UK Health and Safety Executive (UK HSE) have developed a new guidance leaflet for use by anyone who uses oxygen gas in cylinders, in the workplace.

For a copy of the new leaflet, simply click here.

The leaflet describes the hazards from using oxygen and the precautions needed when using oxygen equipment.

If you are an employer, it provides information which will assist you in your risk assessment.

And remember, all employers are legally required to assess the risks in the workplace, and take all reasonably practicable precautions to ensure the safety of workers and members of the public.

This may include a careful examination of the risks from using oxygen in your risk assessment.

There are about 2.4 million eye injuries to people in the USA each year.  35 per cent result from a foreign body entering the eye.  25 per cent result from impacts.  And 15 per cent result from burn injuries to the eye.

About 10 per cent of eye injuries will result in permanent loss of vision to the affected eye.  That's over 240,000 serious eye injuries each year in the USA alone.

Virtually all of the harm caused by incidents to the eyes can be prevented or reduced if workers are using the Think 6, Look 6 process and the correct eye protection.

So what can you do?

Firstly, always use the Risk Tool Box' Think 6, Look 6 hazard management process to identify and evaluate the hazards you face which could lead to eye damage.

●  Identify the hazards and triggers in the task to be performed;

●  If necessary, develop a JSA with appropriate controls for the hazards and triggers; and

●  Attempt to eliminate the hazard wherever possible.

Secondly, aim to create a safe working environment:

●  Make sure you're trained to do the job;

●  Use only the proper tools and following the correct procedure for tool use;

●  Keep non-essential people well away from the work zone; and

●  Inspect your tools and other associated equipment before each use.

Thirdly, wear the appropriate personal protective equipment (PPE):

●  Wear safety glasses to ANSI Z87.1 standard;

●  Use additional full face shielding for jobs which are more prone to create flying debris or spray of substances;

●  Use welding hoods with properly shaded lenses when undertaking or assisting with hot work; and

●  Inspect and clean your eye-wear PPE before each use.

This safety alert from Worksafe in Western Australia highlights the danger when hot-work is performed on tanks or vessels that have previously contained flammable or combustible liquids or gases.

The safety alert highlights how a man was killed in WA when the angle grinder he was using to cut up a disused tank caused an explosion of chemical vapour inside the tank.

Chemical storage vessels and drums that have contained flammable liquids, such as fuels, solvents, and paints can ignite or explode when exposed to “hot work” such as sparks from angle grinders, plasma cutters, welding, oxyacetylene burners and electric metal cutting saws.

This is because flammable liquids give off vapour which has an upper and lower explosive limit that works like a range.  That means that vapour can ignite and/or explode when it is below the upper explosive limit (UEL), but above the lower explosive limit (LEL).  When a flammable or combustible liquid is exposed to heat (from direct or indirect flame), the vapours given off can reach into the range between the LEL and the UEL and ignite.  This reaction can cause a fire or an explosion. Such explosions have resulted in many fatalities occurring or severe burns from the resulting fire.

As recently as July 2012, a West Australian worker was killed when a chemical drum that he was cutting with an angle grinder exploded. The drum had previously contained a flammable liquid.

In another recent case, a Queensland high school student was killed when he was using a plasma-arc torch to convert a drum into a feed bin as part of his agricultural studies. The drum had previously contained diesel oil and the oil vapours that remained in the drum exploded.

The first step towards managing the risks associated with the UEL and LEL of any potentially explosive chemicals is to obtain important safety information.

The manufacturer or supplier of the chemicals must provide this information with the chemicals they provide. The information should be provided by a Material Safety Data Sheet (MSDS) that contains information about the hazards associated with the chemical and precautions for the safe use, transport, storage and disposal.

The MSDS should include information such as the temperature that will allow vapours to rise above the LEL and subsequently ignite, and the levels of exposure that are hazardous to humans through The chemicals should also be labeled in a way that can be easily read and understood.

If a drum of chemicals arrives at the workplace without a safety label and an MSDS attached, it should be returned to the supplier.

Once emptied, the storage containers should be stored in a safe location, away from ignition sources, with their labels still attached.

The best way to prevent an injury or fatality is to ban any form of hot work on or near a vessel or drum that contained (or still contains) flammable or toxic materials.

If hot work must be undertaken, then a Permit to Work should be issued following a thorough assessment of the task to be undertaken, and ensuring all appropriate controls are in place.

It is essential that competent, experienced persons who are familiar with the hazards associated with hot works review all hot work prior to issuing approval for the work to proceed.

It is also critical that workers performing any hot-work are provided with adequate training about the hazards associated with conducting hot work on or near drums that contained flammable or toxic substances.

Hot work involves any activity that can be a source of ignition when flammable material is present, or which can be a direct fire hazard even if flammable material is not present.

Here are some examples of hot work:

 Welding;

 Soldering;

 Cutting metals;

 Brazing;

 Grinding; and

 Drilling into metal which may cause sparks.

Hot work may even include such activities as taking photographs with a non-intrinsically-safe camera.

Countries such as the USA, Australia, Canada, NZ and the UK have regulations requiring safety permits for hot work.

There are also country-specific industry standards from groups such as the National Fire Protection Association (NFPA), the American Welding Society, the American Petroleum Institute (API), and others, which describe safe procedures for hot work.

If hot work requires that you issue hot work permits, you must be properly trained on your plant requirements and procedures before you can issue any hot work permits.

Unfortunately, the majority of incidents associated with hot work occur because the presence of flammable material was not anticipated.

In many cases, flammable vapors flow into the area where the hot-work is being done by a route which had not been anticipated..

Insufficient flammable vapor monitoring of the atmosphere in vessels or other equipment, or in the general work area, is also a frequent contributing cause to hot work incidents.

What you can do:

 Eliminate chemical hazards by draining and cleaning-out tanks, purging residual vapours and establishing an inert atmosphere (e.g., using Nitrogen blanket or filling tanks full with water);

 Isolating areas being subjected to hot-work from other process areas to ensure there is no inward flow, using valves (double block and bleed), caps, blind-flanges or other physical devices;

 Establishing lock-out, tag-out (LOTO) on all isolation points to ensure that isolations cannot be inadvertently breached;

 Understand procedures and permit requirements for safe hot work in your facility;

 Understand the hazards of your process. Know what has to be done to prepare the work area for safe hot work and be sure it is done before you start;

 Anticipate how far sparks or heat can travel or be conducted. Be prepared if work area conditions change;

 Make sure that any activities required during the hot work (for example, monitoring for flammable vapors, maintaining purges) are actually done.

 If you do hot work, make sure you understand everything required for you to do each specific job safely, and follow these safety requirements.

A worthy nomination for a Darwin Award here when a workman in the UK was seriously injured whilst removing the top of a full propane gas tank with an angle-grinder!  We're not sure why anyone would actually want to do this?

In a prosecution by the UK Health and Safety Executive (UK HSE), Southampton magistrates heard that the 29-year-old worker suffered serious burns to his arm and body after propane caught fire.  Now there is a surprise!

The employee was lucky not to have been killed.  Yes, indeed.

Jamie Jewell, a Company Director of a company known as Suffix Pre-Cast, who was "supervising" the workman admitted breaching the UKs Health and Safety at Work Act.  He was fined £2,000 and ordered to pay costs of £2,451.

The UK HSE prosecution alleged that Jewell did not know enough about the hazards of handling propane gas to carry out the work competently or supervise others.

The incident, which involved a full tank of propane gas, occurred at Jewell’s Calmore home on September 2nd  2011.

The dangers associated with performing hot work on oil storage tanks have been re-highlighted by a fatal accident in California.

Cal OSHA is investigating the explosion which occurred when two workers were decommissioning a crude oil tank.

The explosion killed one man, critically injured another and leaves questions unanswered about what safety procedures the men used as they worked on the tank.

The men were using a cutting torch on top of the tank when vapors inside ignited, blowing the 16,800-gallon container some 30 feet in the air and a distance of 79 feet.

The Kern County Fire fire department reported that Cesar Martinez, 24, was blown 40 feet into the air and more than 900 feet distant.

The other worker, identified by their employer Sky-Brand Services as 33-year-old Eric Robles, was also injured.

Both workers believed the tank was empty.

Cal-OSHA investigators determined the two men were assigned to demolish the tank and that Martinez was removing pipe that was to be recycled as scrap metal.

Agency spokesman Peter Melton said “he was using a cutting torch on an enclosed pipe, and apparently gas might have escaped and it ignited". It was unclear who owned the tank and when it was decommissioned, he added.

Sky-Brand partner Dale Hill said Martinez and Robles were removing steel pipeline from the exterior of the tank.

He said the company has done similar work on numerous oil tanks and hasn’t had problems.

“We do everything we can to make sure every precaution is being taken,” Hill said.

In the oil industry, however, the common practice is to keep all flames at least 50 feet away from an oil tank, unless it has been thoroughly cleaned and purged, vented, tested for residual gas and isolated from other "live" processes.

“Fire and gas, they don’t make a good combination,” he said.

Sky-Brand specializes in site cleanup and demolition work, removing scrap metal and selling it, Hill said.

Cal-OSHA’s Melton said the agency’s investigation could take up to six months, during which time it hopes to find out exactly what the two men were doing, what safety precautions were taken, what regulations apply to demolishing such equipment and whether the right tools were being used.

Although Nitrogen is inert and non-toxic, and actually makes-up 78 per cent of the air we breathe, it can become a hazard - with the potential to cause harm - whenever it becomes concentrated in the atmosphere and replaces the oxygen which we need to sustain life.

Out in the open air at sea-level, oxygen makes-up 20.9 per cent of the air we breathe. 

Legislation in the USA and elsewhere establishes a legal lower threshold limit for oxygen in workplaces of 19.5 per cent by volume. 

If the oxygen level falls much below 19.5 per cent, all sorts of health problems may rapidly develop.

One way in which oxygen can drop to levels which are immediately dangerous to life and health is where Nitrogen is used within a facility.  For example, Nitrogen is frequently used to purge pipes and tanks of potentially flammable atmospheres prior to hot work.

These enclosed environments can then be dangerous if appropriate safe-guards are not in place.

A useful process safety beacon on the hazards of Nitrogen can be found by clicking here.

The U.S. Chemical Safety Board (CSB) has determined that an explosion at a DuPont facility in the USA that killed one contract welder and injured his Foreman in 2010, was caused by the ignition of flammable vinyl fluoride inside a large process tank, a hazard which had been overlooked.

The accident occurred at the DuPont chemical plant in Tonawanda. 

The facility produces polymers and surface materials for countertops.

The process for making the polymers involves transferring polyvinyl fluoride (PVF) slurry from a reactor through a flash tank and then into three storage tanks.  The tanks were also inter-connected by an overflow line. 

Days before the incident the process had been shut down for tank maintenance.
 
The tank fill lines were correctly locked out for safety.

Tanks 2 and 3 were repaired and the process restarted, but work on tank 1 was delayed due to a lack of parts.

Although tank 1 remained locked out from the main process, the overflow line remained open which connected tank 1 to tanks 2 and 3.

The CSB found DuPont erroneously had determined that any vinyl fluoride vapor that might enter the tanks would remain below flammable limits.

The CSB determined that flammable vinyl fluoride flowed through the overflow line into tank 1 and accumulated to explosive concentrations.

Although DuPont personnel monitored the atmosphere above the tank prior to authorizing hot work to restart once parts became available, no monitoring was done inside the tank to see if any flammable vapor existed there.

The CSB investigation found the hot work ignited the vapor as a result of the increased temperature of the metal tank, sparks falling into the tank, or vapor wafting from the tank into the hot work area.

The explosion blew most of the top off the tank.

The welder died instantly from blunt force trauma, and the foreman received first-degree burns and minor injuries.

CSB Team Lead Johnnie Banks said, “Our investigation found that DuPont’s process hazard analysis incorrectly assumed that vinyl fluoride in the process could not reach flammable levels in the slurry tanks.  And, critically, DuPont personnel did not properly isolate and lock out tank 1 from tanks 2 and 3 prior to authorizing the hot work.  The flammable vapor was able to pass through the overflow line into the tank the welder was working on, unknown to him or to the operators who signed off the hot work permit.”

Noting the CSB issued a safety bulletin on the dangers of hot work in March 2010, CSB Chairperson Rafael Moure-Eraso said, “I find it tragic that we continue to see lives lost from hot work accidents, which occur all too frequently despite long-known procedures that can prevent them.  Facility managers have an obligation to assure the absence of a flammable atmosphere in areas where hot work is to take place. Explosion hazards can be eliminated by testing inside tanks as well as in the areas around them.”

This is the 2nd fatal accident involving DuPont locations in the USA recorded in 2010.