MEC&F Expert Engineers : THE EXPLOSIVE DANGER OF THE ASPHALT FUMES – A REMINDER AFTER THE ASPHALT TANK EXPLOSION AT LA CROSSE, WISCONSIN

THE EXPLOSIVE DANGER OF THE ASPHALT FUMES – A REMINDER AFTER THE ASPHALT TANK EXPLOSION AT LA CROSSE, WISCONSIN

Over a half-million workers are exposed to fumes from asphalt, a petroleum product used extensively in road paving, roofing, siding, and concrete work. Health effects from exposure to asphalt fumes include headache, skin rash, sensitization, fatigue, reduced appetite, throat and eye irritation, cough, and skin cancer.

We would like to remind you of some of the safety practices that need to be followed when storing, handling, heating, and spraying liquid asphalt products. First, it must be recognized that all asphalt products, when heated enough, are flammable. That means that if you heat any asphalt hot enough, whether it is a cut back, an asphalt cement, or an emulsion, hazardous vapors will be produced.

When these vapors are mixed in proper proportion with oxygen in the air, and come in contact with a source of ignition, a flash fire can occur. The flash may be quite violent, and if enough vapors are present a raging fire may develop. These types of fire can and have burned people very badly, and have killed some.

Many of the asphalt products we use every day are used at temperatures above their flash points. The flash point is the product temperature where a source of ignition will cause the vapors produced to catch on fire. RC and MC cut back asphalts are commonly used at temperatures above their flash points, where flammable vapors are produced. The flash points of asphalt cements may be above the temperatures at which they are used, but they are not far away. You may be using an asphalt cement (AC) at a temperature which is only 20 to 25°F below its flash point. If that AC is overheated in a small area, flammable vapors may be produced. If the water is boiled off of a bit of emulsion, the remains may be asphalt cement or there may be solvents in the asphalt which can produce flammable vapors. In either case the remains are dangerous if overheated. You may overheat a small amount of emulsion, boil off the water, overheat the remaining asphalt, and be producing flammable vapors without even realizing it. If the vapors mix with oxygen and reach a source of ignition, a fire will develop.

The flammable nature of asphalt vapors, and the quick, violent fires which can develop lead us to recommend the following safety precautions.

When heating asphalt in a transport tank, distributor, or tack truck, position the tank broadside to the wind

If any flammable vapors are present, the vapors must escape from the tank through the vent pipe. Typically the vent pipe exits at the bottom of the asphalt tank. Positioning the tank broadside to the wind will allow the wind to disperse the vapors safely away from the burners and other sources of ignition on the truck. If the tank is parked facing into the wind or with its back to the wind, the wind may carry vapors to the burners at the rear, or to other sources of combustion near the engine. If you heat the asphalt tank in a confined area flammable vapors can collect in combustible concentrations.

Always be sure that the heating flues are covered by at least six inches of asphalt before lighting the burners

If the heating flues are not sufficiently covered, the asphalt near the flues will be overheated. Flammable vapors will be produced. ACs will be heated above their flash points. Emulsions will be broken and heated above the flash point of their base asphalt. The flue pipe may be heated hot enough to provide a source of ignition. When this happens, an explosion can occur, which may rupture the tank or blow the man hole cover off. Before lighting the burners it is very important to be sure that the flues are covered over their entire length. Many asphalt tanks are built with a slope or pitch for better drainage. If the tank is parked on a grade, one end or one side of the tank may be higher than the other. You must be sure that the highest point on the flue is covered according to the equipment manufacturer’s recommendation.

Never, under any circumstances light the burners without the flues covered to the depth recommended! If the tank is partially loaded you may need to add more asphalt before heating.

Never spray asphalt while the burners are running

If you spray asphalt with the burners running, you may uncover the flue causing a fire inside the tank. Running the burners while spraying will provide a source of ignition for vapors produced while spraying, causing a fire outside the tank. Be sure the burners are completely out before spraying.

LPG burners will support a flame for several minutes after the valves are shut off.

Keep all sources of ignition away from manholes and tank vents

When you open the manhole flammable vapors may escape. There may be flammable vapors in the tank which are too concentrated to burn. When you open the manhole fresh air or oxygen is introduced. The cigarette in your hand becomes a source of ignition and you may be additional fuel. Flammable vapors are intended to escape out of the tank vent. Keep hand torches, cigarettes, engine exhaust, and other sources of ignition away from these vapors.

Keep vent pipes clear and open

Keeping the vent pipe clear and open will allow the vapors to escape and will keep them from building pressure inside the tank.

Do not operate or weld on a tank which is leaking

A leaking tank must be repaired before continuing use. The repair should be performed by an experienced tank repair shop. An “empty” tank may contain flammable vapors or residual asphalt. You would never consider welding on a gasoline tank. You should never consider welding an asphalt tank either. A tank repair shop will have sensors which can determine if there are flammable vapors present and if the tank is safe to weld.

The hazards identified are very real and very dangerous. Do not take these hazards lightly, as you will see from a small sampling of the asphalt tank explosions or fires that have happened over the years.

Accident: 201345337 - Two Employees Are Injured In Asphalt Tank Explosion

At approximately 7:45 a.m. on May 12, 2010, Employee #1, the senior maintenance member of a two-man crew, and Employee #2 were working from an elevated work platform. The platform was mounted on the back of a trailer, which was mounted to an asphalt tank. The employees had begun bypassing the normal asphalt storage tank to prepare for its five-year to seven-year cleaning. They placed a bypass valve in position to route the asphalt from the permanent tank to the temporary, trailer-mounted tank. Most of the asphalt piping was heated with a steam jacket encircling the pipes.

However, the piping that ran from the bypass valve to the temporary tank was encircled with tubing that was heated by steam. The employees complained that the steam tubing, also referred to as steam tracing, was not wrapped tight enough, thereby preventing the pipe from getting hot enough to turn the hardened asphalt back to its liquid (melted) state. The employees then attempted to repair the clogged pipe. As was reported to be the normal practice, Employees #1 and #2 went to the end of the asphalt piping outlet and began heating the last bend of the piping with a propane torch. The piping outlet was located directly over the top of the manhole opening of the heated asphalt tank. The tank was reported to be 300 degrees to 400 degrees Fahrenheit, at that time.

During the site visit, approximately five hours later, the tank temperature gauge read approximately 260 degrees Fahrenheit. After an undetermined amount of time that Employees #1 and #2 were using the propane torch to heat the piping, an explosion occurred in the asphalt tank. A witness described the explosion as a flame which shot 30 feet above the manhole cover and quickly descended back into the tank. This witness also stated that he could no longer observe the employees standing on the platform. Employee #1 remained on the platform and suffered asphalt burns and fractures to his face, where an item impacted it during the explosion. Employee #2 fell from the work platform, approximately 9 feet 5 inches to the concrete surface.

Employee #2 suffered asphalt burns to his body and face, in addition to a hip fracture. A radio call for emergency response was broadcast throughout the company. The company Emergency Response Team doused the flames and provided initial first aid to Employees #1 and Employee #2. Both employees were transported to the University of Kansas Burn Unit and were hospitalized. At the time this report was written, they were currently being treated. Both employees were in critical but stable condition and were expected to recover. The safety leader stated that Employees #1 and #2 were wearing coveralls, steel toed shoes and safety gloves. However, they did not find evidence that the employees were wearing face shields and/or chemical goggles, as called for in the PPE hazard assessment

Worker dies in explosion of tank at asphalt plant

January 30, 2006

WEST SIDE — An explosion at a Chicago asphalt company Sunday killed one worker.

The explosion occurred just after 1 p.m. Sunday at Gardner Asphalt Corp., 4718 W. Roosevelt Rd., where one of four outdoor tanks caught fire, said Kevin MacGregor of the Fire Department.

The nearly 30-foot-tall tank most likely contained asphalt, which ignited for an unknown reason, MacGregor said, adding that firefighters prevented the other tanks from catching fire.

"We will be doing an investigation for cause and the origin of the fire," he said.

The worker, who was pronounced dead at the scene at 2:35 p.m., was not publicly identified because his family had not been notified, said a spokesman for the Cook County medical examiner.

No one at Gardner was available for comment Sunday.

Asphalt tank in Jessup explodes

January 31, 2006

A liquid-asphalt storage tank exploded into flames at an Owens Corning shingle plant in Jessup yesterday evening, drawing dozens of firefighters from Howard, Anne Arundel and Prince George's counties to prevent the blaze from spreading to adjacent tanks. There were no injuries.

The cause of the blaze on the grounds of the Baltimore-Washington Industrial Park, off U.S. 1, could not be immediately determined, said Bill Mould, a spokesman for Howard County's Department of Fire and Rescue Services. The fire was reported at 5:33 p.m. and was declared contained about two hours later. But firefighters planned to stay to monitor the situation throughout the night.

"There was an explosion and the roof continued to burn," said Jason Saragian, a spokesman for Owens Corning. "How and why is still the focus of the investigation."

Aerial tower trucks were used to pour water onto the nearby tanks of liquid asphalt, which is used to make roof shingles. Plumes of black smoke filled the air, and the exterior of the 3,300-gallon asphalt tank appeared to be on fire.

Fire officials said they did not put water directly on the blaze for fear of bursting the tank. Instead, they sprayed water on the exterior to keep it cool. A chemical powder, typically used for aircraft fires, was brought from Baltimore-Washington International Thurgood Marshall Airport to help extinguish the fire.

The fire erupted in an industrial area in the 8200 block of Patuxent Range Road. No homes are in the immediate vicinity. Officials from the Maryland Department of the Environment were on the scene, assessing the risk from runoff and smoke.

Too Much Pressure in Storage Tank Blamed For Bango Oil Explosion

Updated: Wed 9:23 PM, Jan 08, 2014

FALLON, NV - It was nearly one month ago that an explosion and fire rocked the Bango Oil plant west of Fallon, sending a thick plume of black smoke into the chilly morning air.

One worker was severely burned.

It took firefighters from Churchill County and the Fallon Naval Air Station two hours to extinguish the flames.

A preliminary report from the investigation by the fire department and the state fire marshal's office released Wednesday says it all began with too much pressure in an asphalt storage tank.

Churchill County Fire Chief Fred Rogne says that led to some of the hot asphalt oil being vented from the top of the tank.

The oil splashed down on 24 year old Daniel Snodgrass who was working below. The oil, which had been heated to 500 degrees as part of the recycling process, burned him.

Snodgrass was apparently heating pipes in the bitter cold, using a hand held burner with an open flame.

That flame ignited the oil, causing the fire and the explosion that followed as the tops of storage tanks blew off as they're designed to do.

The statement leaves some questions unanswered including the still unexplained high pressure in the storage tank. In a press release issued the day after the incident, the company says the plant was operating normally at the time.

The Occupational Safety and Health Administration is conducting its own investigation. Results could be available in two weeks.

Snodgrass suffered second, third and fourth degree burns over more than half of his body.

He was flown to the burn center at UC Davis Medical Center in Sacramento in critical condition.

A hospital a spokesperson tells us he's now listed in good condition meaning his vital signs are stable and indications are excellent.

His parents, Kevin and Lois Snodgrass, say he has good days and bad, but is enduring a daily routine of painful treatment and rehabilitation.

Daniel Snodgrass is the oldest sibling in a family of nine which now faces months of unexpected expenses.

An account has been set up to aid them. Donations can be made at any Wells Fargo Bank branch.

Fatal Explosion Brings Framingham Employer OSHA Citations

HARTFORD -- A July 3 explosion of an asphalt tank at a Framingham, Mass. company that killed a worker could have been prevented if the company had taken the proper safety precautions, according to the U.S. Labor Department's Occupational Safety and Health Administration (OSHA).

As a result of the agency's investigation of the fatal explosion, OSHA has issued citations alleging willful and serious safety violations to Triram Corporation of 721 Waverly St., including proposed penalties totaling $52,500.

The investigation revealed that a contractor was directed to do welding work on top of a 10,000-gallon tank without being told about the tank's volatile contents.

"This was a tragedy that could have been avoided," said Richard Fazzio, OSHA's area director for northeastern Massachusetts. "The company should have followed required safety procedures and informed workers about the dangers of the hazardous materials in the workplace."

The alleged "willful" violation, which carries a proposed penalty of $35,000, charges Triram Corporation with failing to implement a hazard communication program. The company did not inform the welding contractor about hazards related to flammable vapors produced by heated asphalt and chemicals in the tank being welded.

The company is also charged with five alleged "serious" violations of OSHA safety standards for: failing to ensure containers of hazardous chemicals were labeled with proper contents and hazard warnings; failing to assure that containers of toxic or flammable substances were either filled with water or cleaned thoroughly and vented and tested prior to welding, cutting or heating; failing to equip above-ground storage tanks with a pressure release device; and exposing employees to fire or explosion from a tank that stored flammable liquid adjacent to a main building. Proposed fines for these alleged violations total $17,500.

OSHA defines a willful violation as one committed with intentional disregard or plain indifference to the requirements of the Occupational Safety and Health Act and regulations. It defines a serious violation as one in which there is substantial probability that death or serious physical harm could result, and the employer knew, or should have known, of the hazard.

Triram Corporation has 15 business days from receipt of these citations to either elect to comply with them, to request and participate in an informal conference with the OSHA area director, or to contest them before the independent Occupational Safety and Health Review Commission. OSHA's Methuen area office conducted this inspection. Its telephone number is 617-565-8110.

The Occupational Safety and Health Administration is dedicated to saving lives, preventing injuries and illnesses, and protecting America's workers. Safety and health add value to business, the workplace and life. For more information, visit www.osha.gov.

Accident: 550509 - Employee Dies In Explosion After Using Torch On Asphalt Tank

Employee #1 was directed to use an open-flame propane torch to unclog a pipe line/elbow on top of an asphalt tanker trailer. The pipe line/elbow was blocked with solidified asphalt. The blockage was suspected to be located at the pipe elbow on the gasoline-powered submerged pump. The employee checked the side motor mount area with a live, open-flame propane torch while the internal asphalt tanker heaters were operating (heating the asphalt and creating off-gassing within the tank's interior). It is suspected that the torch ignited combustible vapors/gases that were seeping out around the motor mount. The explosion blew the submerged pump off its mount and into the employee's upper body and head. The employee was blown off the platform and landed on the ground. He was burned over his upper body by the flash fire. He was pronounced dead upon arrival at a local hospital.

Employee Killed, Others Injured In Asphalt Tanker Explosion

Accident: 14333595 -- Report ID: 0420600 -- Event Date: 05/11/1992 - Florida Tank Services, Inc.

Employee #1 was at an establishment that repairs bulk fuel transport trucks, repairing a small leak on the rear bulkhead of an aluminum tanker that had last contained an asphalt emulsion. Employee #4 was assigned as his helper. Other welders recommended opening and venting the tanker and then entering the tank to repair the leak from the inside. The company had no specific procedures for "safing" asphalt tankers, and Employee #1 apparently chose to try to repair the leak from the outside. Once the tanker was backed into the workbay, Employee #1 attempted the repair with an arc welder. The repair failed because of product contamination around the leak. Employee #1 then lowered the tanker at the front to force the remaining product to the front and away from the leak, and used an oxygen/acetylene torch in an attempt to melt the asphalt emulsion away from the leak, but did not open the top hatches and vent the tank. An explosion occurred and Employee #1 suffered fatal head injuries. Employee #4, who was next to the tanker, was knocked to the floor and suffered from ringing in the ear, dizziness, and headaches from inhalation of asphalt fumes and smoke. Employee #2 sustained bruises to his ribcage when thrown into a work bench by the explosion. Employee #3 sprained his left knee when the explosion knocked him from the top of a nearby tanker. The building was heavily damaged and the tanker was destroyed. Causal factors include: a lack of established procedures for safing an asphalt tanker before cutting/welding; inadequate supervision of welding operations; absence of employee hazard training and unsafe work practices.

Employee Is Killed When Tank Explodes While Cutting On It

Blacklidge Emulsions Inc

Employee #1 was cutting on a tank that contained SSI Asphalt emulsion using acetylene and oxygen. The tank exploded killing him.

Firefighters battle blaze at Monroe asphalt plan in Michigan

September 2014

Firefighters from Frenchtown and Monroe Townships and the City of Monroe doused a liquid asphalt holding tank that caught fire at the Michigan Paving & Materials’ plant at the Port of Monroe Tuesday evening that sent large plumes of black smoke into the air.

The three departments knocked the fire down quickly with both foam and water after arriving about 5:45 p.m. at the plant off E. Front St. just west of the DTE Monroe Power Plant.

The plant is the largest liquid asphalt blending facility in the world, according to Paul LaMarre, director of the port who spotted the blaze and called 9-1-1. The cause of the blaze was not available.