O&M

Positive action with glove bags can eliminatenegative-pressure needs

Issue 5 and Volume 100.

Positive action with glove bags can eliminatenegative-pressure needs

Recent regulations from the Occupational Safety and Health Administration (OSHA) allow electric utilities to use glove bags for a wider variety of applications, in many cases saving time and money and reducing potential for personnel exposure to asbestos. New standards allow glove bags to be used in maintenance operations or removal of asbestos from straight runs of pipe with no size limitations.

Glove bags can also be used on elbows and otherconnections if the glove bags are designed for theparticular configuration. On-site construction of negative pressure enclosures is no longer required forthese situations. “Using glove bags, we can perform many jobs at about one fourth the cost and with half the manpower that would be required to construct negative pressure enclosures,” said Ronald H. Robishaw, Consumers Power mechanical maintenance supervisor for the Essexville, Mich., facility.

“In many instances, glove bags allow a safer and cleaner operation.” At Consumers Power, glove bags are used most frequently when in-line valves in steam lines are being serviced or replaced. OSHA has noted that glove bags offered the same or better protection for workers and the environment.

Potential savings

To achieve the potential savings, utility managers who are involved with asbestos work need to become familiar with the new regulations and then determine how they apply to specific company facilities, said Kurt Ross of Grayling Industries Inc. Although the new regulations represent a step toward recognizing some workplace realities, requirements are specific and sometimes complicated.

“For some jobs where standard models of glove bags are not appropriate, we can save up to 30 percent by using custom-fabricated glove bags, rather than constructing negative-pressure enclosures ourselves,” said Jim Plecker, Insulation Specialties Inc. project supervisor.

Working within a negative-pressure enclosure can lower productivity, which also adds to the cost of the job, although these costs are hard to quantify.

In some cases, heat may limit the time a worker can perform abatement work without becoming dehydrated. Glove bags can reduce the time required to perform scheduled maintenance or to handle emergency servicing.

OSHA requirements for glove bags include both bag material and design features. OSHA specifications include:

¥The minimum thickness for glove bag plastic is six mils.

¥Glove bags must be impervious to fiber release.

¥Glove bags must be constructed without a bottom seam or weld. Concern regarding failure from the weight of debris resting on the bottom seal created this provision.

¥Glove bags must be designed for particular applications and used without modifications.

The new OSHA regulations specify a number of procedures that must be followed to assure workers using glove bags and other workers in the area will not be exposed to asbestos concentrations beyond permissible limits.

They include: the glove bag must completely cover the section of pipe or other structure where the work is to be performed; loose or friable material adjacent to the glove bag operation must be wrapped and sealed in two layers of six-mil plastic or otherwise rendered intact; each glove bag may be used only once. It may not be moved or slid down the pipe; glove bags must be smoke tested for leaks prior to use, and any leaks must be sealed; glove bags may not be used when surface temperature exceeds 150 F; workers must wear respiratory protection; critical barriers over openings must be provided; at least two people must perform glove bag removal; prior to disposal, glove bags must be collapsed by removing air with a high-efficiency particulate-air filter vacuum; and cleanup must be prompt, and all waste and debris contaminated with asbestos must be placed in leak-tight containers.

When used properly, glove bags have proveneffective in preventing exposure to asbestos. “Monitoring of work done with glove bags has shown consistently low levels of asbestos, well within permissible limits,” said Robishaw. “The safety of employees who work with asbestos and of other workers is our primary concern.”

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