NFPA Journal - March/April 2013 - (Page 62)

FEATURE NAME Scenes from the Field Marine chemists at work—and the kinds of incidents they try to prevent Crude oil vapor was apparently ignited by hot work on this barge in Texas. Two workers were injured, and the barge was destroyed. Barge explosion Carbon monoxide exposure Carbon monoxide incident Two workers were attempting to make a minor repair to a vent riser on the expansion dome above a cargo tank on a barge. Contrary to regulations established by both the Occupational Safety and Health Administration and the U.S. Coast Guard, the repairer did not call for a marine chemist to test and inspect the barge and then post a marine chemist’s certificate on the barge before the hot work repair began. As the workers were finishing a weld to a pipe collar, crude oil vapor from the residue of three previous cargoes was apparently ignited by welding sparks. One of the workers reported hearing a rumbling sound that was followed by a massive explosion. A witness in a passing tug boat stated that the blast was so strong that it blew out the windows in the pilot’s house of his boat. The two workers suffered only minor injuries, though one was thrown into the waterway and had to be rescued by a passing vessel. Both were treated at a local hospital and released. The barge was declared a total constructive loss. Had a marine chemist been consulted, the work would not have occurred until the barge was in a safe condition, which could have been accomplished by either washing and gas-freeing the tanks or employing the use of inert gas to prevent the risk of explosion and fire. A worker was assigned the task of cleaning the hold of a fishing vessel, and brought a pressure washer powered by an internal combustion engine into the hold. As the worker was cleaning the hold, carbon monoxide (CO) quickly accumulated in the poorly ventilated space. The worker was not immediately aware that he was being poisoned, because CO is an odorless and colorless gas. At some point he did recognize he was in trouble and managed to exit the hold, only to collapse on the deck. He was revived by paramedics, but died en route to the hospital. Work activity of this type does not require a marine chemist’s certificate. However, OSHA directs an employer to designate a “competent person,” someone capable of recognizing and evaluating workplace hazards or unsafe conditions and is capable of taking action to ensure the safety of employees. When internal combustion engines on portable equipment exhaust into an atmosphere below decks, such as a fish hold, the competent person is required to test for CO in the atmosphere to verify that dangerous concentrations do not develop. If the concentration of CO exceeds the OSHA permissible limit (PEL) of 50 ppm (0.005% by volume), then workers need to be evacuated from the space or area until safe conditions are reestablished. Thirteen days after the fatal CO accident in Seattle, a marine chemist was called to a large factory trawler in a shipyard to inspect and certify a repair involving hot work in the trawler’s engine room. As the marine chemist was preparing for the inspection, he noticed workers were prepping the exterior deck for a new coating of paint. To protect the work area, the workers had erected a tent-like structure to keep the area dry during inclement weather. As the marine chemist finished checking his equipment for the job in the engine room, he heard an internal combustion engine starting and being warmed up for work. He immediately headed up the gangway to find a worker using a gasoline-powered “rust-buster” to descale the deck. The machine had been running for two or three minutes. The marine chemist’s CO detector indicated a concentration of 150 ppm, well above the recommended levels. The marine chemist shut down the operation and provided instruction to the workers about the hazards of using gasoline-powered machines and the need for proper ventilation in an enclosed space. Only after safe conditions were established did the work resume. March 25, 2010 Ingleside, Texas 62 NFPA JOURNAL MARCH/APRIL 2013 May 17, 2012 Seattle, Washington May 30, 2012 Tacoma, WA Photograph: U.S. Coast Guard

Table of Contents for the Digital Edition of NFPA Journal - March/April 2013

NFPA Journal - March/April 2013
Contents
First Word
In a Flash
Perspectives
Firewatch
Research
Heads Up
Structural Ops
In Compliance
Buzzwords
Outreach
Electrical Safety
Wildfire Watch
Cover Story: Storage Occupancies
Fifty Years of Smoke Detection
Industrial Occupancies
Chicago 2013
Fire Analysis + Research
Section Spotlight
What’s Hot
Looking Back

NFPA Journal - March/April 2013