Current LOTO rules require all energy be disconnected before serving and maintaining industrial machinery.
OSHA sought comments on its existing standard that dates to 1989, calling for controlling sources of energy by energy isolating devices (EID) and changing that to circuit control-type devices. OSHA received more than 85 comments by the agency's deadline of Aug. 19.
An EID is a mechanical device that physically prevents the transmission or release of energy — for example, a manually operated circuit breaker or a disconnect switch — deenergizing the machine and physically locking it out.
Circuit control-type methods use electronic control and switches to protect employees from potentially hazardous released energy.
The original OSHA regulations specifically excluded circuit control-type devices from lockout/tag-out, including push buttons, selector switches and other similar devices.
But advocates of changing OSHA regulations to circuit control devices — including the Plastics Industry Association — say the technology has dramatically improved since 1989, making the sensing devices a reliable source to prevent employees from injury from unexpected hazardous energy. The standard should be modernized to reflect the new technology, they argue.
ANSI's B11 standards committee has 32 members from companies and industry organizations, including the Plastics Industry Association, the Robotic Industry Association and the Association for Packaging and Processing Technology (PMMI).
The Plastics Industry Association and PMMI also made separate comments supporting the change.
Cost reductions would come from shorter times for maintenance and servicing activities, the Plastics Industry Association said. The trade group asked its members to give examples in which safety control circuits, rather than lockout/tag-out, improve productivity.
The plastics association gave mold changes as one example to show the difference. Applying lockout/tag-out to mold changes — instead of the industry's current method of using circuit controls — would remove one hour of production each day for one press if LOTO rules called for shutting down the heaters that keep the plastic in a molten state, or 30 minutes if the heaters did not have to shut down.
The Plastics Industry Association estimated there are about 450 factories in Michigan that operate an average of 30 injection molding machines. Based on two mold changes per week on 30 presses and a cost of $60 per machine per hour, the downtime could add up to about $187,000 when shutting down the heaters or $93,000 if the heaters can stay on.
Using traditional LOTO vs. control circuit systems would increase the time to complete setup tasks by about 50 percent, the association said.
The plastics trade group also gave comparison data for other processes, such as work changes on flexographic presses, blown film extrusion, pallet wrapping equipment and programing a robot at a packing station.
PMMI, the packaging trade association, said the current LOTO regulation "has created significant compliance defense costs, impeded the use of advanced technologies and best practices and inadvertently affected industry competitiveness in a negative manner." PMMI also gives time and cost numbers showing the circuit control-type methods are improvements over LOTO. Examples include cleaning and clearing jams in a can filling line and a bottling line.
PMMI's filing shows examples of alternatives that are already being used in high-output packaging operations, including slide locks to prevent an unexpected restart, "trapped keys" that only can be accessed by qualified people and a system that uses two independent safety circuits for each variable frequency drive on an automated robotic case packer.
The Council of Manufacturing Associations also supports OSHA considering the control circuit type devices as an alternative to LOTO. Members, including the National Association of Manufacturers, surveyed their membership and got 70 responses.
"There were virtually no reported instances of control circuit device failure," the council said. However, in "more process-focused industries, the preference is the control circuit needs to be physical and the worker must be knowledgeable of the system," the manufacturing group wrote. "There must be a certainty that disabling the control circuit would prevent the associated piece of equipment from moving or becoming energized in some way."