CHAPTER 3

ASBESTOS DELAGGING FACILITIES

3-1 FUNCTION。 An asbestos delagging facility provides a complete workshop to remove asbestos insulation from piping and mechanical equipment during ship repair。 The ventilation system design discussed in this section is for activities with extensive asbestos removal operations。 The design includes: shop and equipment space, clean and dirty locker rooms for men and women, and administrative space to support the coordination and monitoring of facility operation。

3-2 OPERATIONAL CONSIDERATIONS

3-2。1 Airborne Contamination。  When asbestos insulation is delagged, the asbestos fibers are dispersed into the air, creating a health hazard。 29 CFR 1910。1001, Asbestos, General Industry and 29 CFR 1915。1001, Asbestos, Shipyards dictate protective measures for workers in these facilities, including respirator protection and impermeable outerwear。 The regulations also prescribe wetting the asbestos material with amended water (water containing a surfactant), if practicable, to reduce the potential for asbestos fibers to become airborne。

3-2。2 Heat Stress。  The physical nature of the work and impermeable outer garments worn by the workers creates heat stress conditions。 Provide supplied air respirators with vortex tubes as specified in EPA-560-OPTS-86-001, A Guide to Respiratory Protection for the Asbestos Abatement Industry。 Consider cooling the replacement air when supplied air respirators are not available。 Consider using "micro climate cooling" or "cool suits," mechanically cooled garments, for inpidual workers。

3-2。3 Employee Workflow。 Workers enter the clean locker rooms through the administrative area。 They put on protective outerwear and proceed to the shop area。 After performing delagging, workers vacuum their protective outerwear and dispose of them in containers provided in the decontamination area。 They enter the dirty locker rooms and remove the remainder of their work garments。 Workers then proceed to the clean locker rooms via the showers, which act as a barrier to the migration of asbestos fibers。

3-3 TYPICAL FLOOR PLANS。 Design floor plans to meet the requirements of 29 CFR 1910。1001 and 29 CFR 1915。1001 and paragraph 3-2。3。 Figure 3-1 shows a sample delagging facility floor plan。

Figure 3-1。  Delagging facility floor plan。

3-4 DESIGN CRITERIA。 Design the facility using general technical requirements in Chapter 2 of this UFC and the specific requirements in this Chapter。

3-5 EXHAUST AIR。 Design the exhaust air system to generate a minimum capture velocity of 0。762 m/s (150 fpm) to capture all the contaminants at the source。

3-5。1 Hood Design。  Design asbestos delagging hood to enclose the work piece as much as possible。 Do not use small portable hoods with flexible ductwork because they do not provide consistent capture。

3-5。1。1 Typical Hood Design for High Profile Work Pieces。  Figure 3-2 shows a hood design consisting of a workbench with a central, circular area。 Mount the circular area on sealed bearings to allow easy turning of heavy work pieces。 This design is best for high profile work pieces (for example, boilers, pumps)。 The hood captures contaminants through the slots into an exhaust plenum。 Design each hood with:

a。 Two cleanout doors on the front and two doors on the sides of the hood for easy access to asbestos debris。  Provide two small cutouts in the outer