BATTERIES INCLUDED
TRAINING NOTEBOOK
A recent accident on Interstate 10 outside of Tucson, Arizona illustrates how we occasionally can overlook some important consideratons when responding to routine and seemingly insignificant hazardous-materials transportation incidents. An 18-wheeler loaded with car batteries had been involved in a wreck on the freeway. A number of the batteries had been knocked off their wood pallets on impact, and some were leaking from cracked cases and broken terminal posts. Battery spills have become so routine that even the U.S. Department of Transportation does not require the carrier to submit a written incident report unless such a spill results in injuries or damages over $ SO,000.
One of our Arizona Department of Public Safety commercial vehicle safety specialists helped the responding fire department assess the scene. Fire department members threw some dirt into the trailer where battery’ acid had spilled on the floor and prepared the vehicle to be hauled from the freeway by a wrecker. It wasn’t until we started asking a few questions that we realized some additional steps were necessary.
1 lazardous-materials interstate transportation is governed by DOT regulations. In 49 Code of Federal Regulations (49 CFR) Parts 171-179, DOT’S Research and Special Programs Administration publishes these rules, which also have been adopted by most states for intrastate transportation. In addition to general requirements for all hazardous-materials packages (also applicable to the load of batteries), there are specific provisions dealing with hazardous materials involved in accidents.
According to 49 CFR Part 177.801, which applies to highway transportation: “Hazardous materials…may be accepted and transported by private, common and contract carriers by motor vehicle engaged in interstate or foreign commerce, provided they are in proper condition for transportation.shipments of explosives or other dangerous articles not in proper condition for transportation, or loaded or stayed as required…must not be accepted for transportation or transported.”
The regulations provide further extensive guidance in 49 CFR Subpart D, Vehicles and Shipments in Transit, Accidents, Parts 177.853 through 177.861. There are specific requirements dealing with the various hazard classes of materials, and the repair of broken packages is addressed. In the case of corrosive materials, in this case sulfuric acid (battery acid), a good deal of latitude is provided, but obviously the trailer had to be safe before it left the scene.
POTENTIAL PROBLEMS
Although it is not clearly covered in some handling guides, sulfuric acid reacts with many metals to produce explosive hydrogen gas. Further, sulfuric acid has an extremely low timeweighted average exposure level of only 1 milligram-per-cubic-meter, with a short-term exposure limit of milligrams-per-cubic-meter. The immediately dangerous to life and health level for sulfuric acid is 80 milligramsper-cubic-meter.
Since accidents involving batteries are fairly common, we had been concerned in the past about battery acid exposure. Although sulfuric acid in batteries is not very volatile, the Arizona Department of Public Safety conducted field testing with Draeger tube detection instruments. Our tests showed that under normal conditions, vapor concentrations from small spills of battery acid will not rise above the 1 part-per-million level. Therefore, the vapor hazard is nonexistent.
A final problem involving the transportation of batteries is the potential for fire from the accidental shorting of the terminals. This has been such a common occurrence in the past that the hazardous-materials transportation regulations contain several specific provisions to guard against battery terminal shorting. Before the damaged trailer left the scene, we had to ensure that there were no shorted battery terminals.
(Photo by author.)
INSPECTION AND REMOVAL
We determined that entry into the trailer was necessary to inspect for possible hydrogen gas buildup or generation, the conditions of leaking and damaged batteries, continuing leaking battery acid, and battery terminal shorting. We held a safety briefing with the fire department, who provided the backup rescue team and stood by with a charged line. We first used a flammable gas detection meter to check for hydrogen around the trailer’s rear door prior to opening it. We then inspected the entire load to ensure that it could be safely transported to the wrecking company yard, where the damaged batteries would be overpacked for return to the shipper.
We did not find a flammable concentration of hydrogen, and the damaged batteries had stopped leaking their sulfuric acid electrolyte. None of the terminals were in danger of shorting, and the batteries were safely stacked and braced for the trip to the wrecker yard. We made sure that there was enough dirt inside the trailer to soak up any small amounts of battery acid that might spill during the trip. Once we were satisfied that nothing would happen with the damaged load, it was towed away.
Often we become so used to responding to everyday transportation accidents that we may overlook some significant regulatory requirements or common-sense safety considerations. However, consider the danger potential for every’ hazardous-material load transported, even the “routine” ones.
