6.1 Regulated Areas, Work-Area Preparation, Critical Barriers & Polyethylene Specifications

6.1 Regulated Areas, Work-Area Preparation & Barriers

Quick Answer: OSHA requires all Class I, II, and III asbestos work to take place in a regulated area that is demarcated, has restricted access, and is posted with DANGER / ASBESTOS / MAY CAUSE CANCER / CAUSES DAMAGE TO LUNGS / AUTHORIZED PERSONNEL ONLY signs. On New Jersey subcode projects (N.J.A.C. 5:23-8.15), the contractor pre-cleans, shuts down and seals HVAC and electrical systems, and seals penetrations. The contractor then installs critical barriers of two layers of 6-mil polyethylene, covers floors with two layers (turned up the walls 12 and 24 inches), and covers walls with one layer that overlaps the floor sheeting by at least 18 inches.

The OSHA Regulated Area (29 CFR 1926.1101(e))

• When required: All Class I, II, and III work, regardless of measured levels. Any other asbestos operation also requires a regulated area where exposure exceeds, or may exceed, a PEL.
• Demarcation: The area must be marked in a way that minimizes the number of people inside and protects people outside. Signs, barrier tape, and walls can all be used.
• Access: Only authorized persons.
• Respirators: Anyone entering must wear the respirators required for the work.
• Prohibited activities: No eating, drinking, smoking, chewing tobacco or gum, or applying cosmetics inside the regulated area.
• Supervision: All work in the regulated area must be supervised by a competent person. In New Jersey, the licensee must also keep a permitted supervisor on site throughout the project.
• Multi-employer sites: The asbestos contractor must inform other employers about the nature of the work and the regulated area. Employers of workers adjacent to the area must check barrier integrity daily and move their people if a breach exposes them (1926.1101(d)).

Warning Signs (1926.1101(k)(7))

Signs must be posted at every approach to a regulated area, far enough away to let a person read them and take protective action before entering:

DANGER
ASBESTOS
MAY CAUSE CANCER
CAUSES DAMAGE TO LUNGS
AUTHORIZED PERSONNEL ONLY

Where respirators and protective clothing are required, the sign also states: WEAR RESPIRATORY PROTECTION AND PROTECTIVE CLOTHING IN THIS AREA. The older wording, "CANCER AND LUNG DISEASE HAZARD," was replaced when OSHA updated its signs and labels under the Hazard Communication Standard revisions. On subcode projects, New Jersey also requires caution and/or danger signs in clearly visible locations (N.J.A.C. 5:23-8.15(d)1).

New Jersey Subcode Preparation Sequence (N.J.A.C. 5:23-8.13, 8.15(d)-(f))

The subcode sets both what must be done and in what order. Preparation may start once the construction permit is issued, with the AST observing. No removal begins until the AST approves the pre-commencement inspection (Section 1.4).

Step 1: Pre-Project Cleaning

The owner decides whether all surfaces in the work area must be HEPA-vacuumed and/or wet-wiped before the project, so that existing dust does not interfere with final inspection and clearance. That cleaning is done by trained owner employees or made part of the licensed contractor's scope (N.J.A.C. 5:23-8.13).

Step 2: Signs, Removable Objects, Decon Unit, Systems

1. Post caution and/or danger signs.
2. Workers with New Jersey permits, or owner employees who have completed an NJDOH-approved maintenance/custodial or worker course, wet-clean and/or HEPA-vacuum removable objects such as furniture, equipment, drapes, and curtains, then remove them. The cleaning cloths are asbestos waste. If the room and objects are shown to be uncontaminated, other employees may move them.
3. Build the decontamination unit (Section 6.3).
4. Shut down and seal off all electrical, heating, cooling, ventilating, and other air-handling systems. With ASCM approval, work-area lighting and receptacles may stay in use if they are protected by ground fault circuit interrupters (GFCIs) and can be cleaned afterward.
5. Post written emergency procedures covering medical emergencies, fire evacuation, loss of power or water, and repair of barrier breaches.

Step 3: Initial Activity in the Work Area (N.J.A.C. 5:23-8.15(f))

The subcode lists these steps in order:

1. Remove HVAC filters, wet them, and double-bag them in labeled polyethylene bags. Squeeze out excess air and seal the bags with duct tape.
2. Wet-clean and/or HEPA-vacuum non-removable items, such as radiators and suspended light fixtures, and cover them with two layers of poly taped securely.
3. Detach and wet-clean removable electrical, heating, and ventilating equipment connected to asbestos surfaces. Remove it from the work area and reinstall it only after decontamination and satisfactory final air results.
4. Seal all floor, wall, and ceiling penetrations with suitable material such as expanding foam before covering surfaces with poly.
5. Install critical barriers over all openings between the work area and clean areas: windows, doorways, elevator openings, skylights, corridor entrances, floor and sink drains, ducts, grilles, grates, and diffusers. Critical barriers are two layers of poly taped, stapled, glued, or held with wood battens. Floor drains are sealed individually and then covered with the floor poly. Separation barriers (framed walls) may support critical barriers but may not block any required means of egress.
6. Lay floor sheeting.
7. Hang wall sheeting.
8. Install HEPA air-filtration units sized for at least one air change every 15 minutes (Section 6.2).

Polyethylene Specifications

Occupied buildings add requirements (N.J.A.C. 5:23-8.19(c)3):

• Floor layers are individually sealed.
• The wall layer is individually sealed to the wall.
• No seam may stop within 12 inches of a corner.
• Sheeting overlaps at least 12 inches between seams of adjacent layers.

The work area must also be separated from occupied space by rigid separation barriers: 2 x 4 studs 16 inches on center with at least 1/2-inch plywood, or equivalent metal framing with 1/2-inch gypsum board, all seams caulked, and two layers of poly on both sides.

The Only Permitted Openings

All vertical and horizontal surfaces, except the ACM being removed, are sealed with watertight poly. The only permissible exceptions to total enclosure are (N.J.A.C. 5:23-8.15(e)3):

1. The entrance airlock with showers and decontamination chamber.
2. A debris-removal airlock for cleaning and removing waste.
3. Staircases.
4. Controlled make-up air inlets.

Torn or damaged poly must be repaired or replaced immediately.

Why the Layers Overlap the Way They Do

The floor poly goes down first and turns up the walls. The wall poly then hangs over that turn-up, like shingles on a roof. Amended water sprayed on walls then runs down the face of the wall sheeting, onto the floor poly, and stays inside the "bathtub" instead of seeping behind it. Keeping seams away from wall-floor joints and corners removes the most common leak paths.

OSHA Provisions That Apply Everywhere

Outside subcode buildings, OSHA sets performance requirements rather than New Jersey's layer-by-layer rules. For Class I work, 29 CFR 1926.1101(g)(4) requires:

• Critical barriers over all openings to the regulated area, or another isolation method proven by perimeter monitoring, for any Class I job removing more than 25 linear feet or 10 square feet of TSI or surfacing ACM. The same applies to any Class I job without a negative exposure assessment, or where other employees work in adjacent areas.
• HVAC isolation on every Class I job, by sealing with a double layer of 6-mil plastic or the equivalent.
• Impermeable drop cloths beneath all removal activity, and all objects in the regulated area covered with plastic secured by duct tape or an equivalent.
• Ventilation that moves contaminated air away from employees' breathing zones toward HEPA filtration when there is no negative exposure assessment or a PEL is exceeded.

Project specifications for private buildings often copy the New Jersey layering pattern because it meets these performance requirements.

Exam Traps

• Wall layers on a subcode job: one layer, not two. Two layers apply to floors, critical barriers, and covered fixtures.
• Floor turn-ups: 12 inches for the first floor layer and 24 inches for the second. Wall sheeting overlaps the floor sheeting by 18 inches.
• Order of work: Seal penetrations with foam before covering surfaces with poly. Critical barriers go up before floor and wall sheeting.
• Floor drains are sealed individually and then covered by the floor layers.
• Egress: Barriers may not block required exits.

Scenario

At a municipal library project, the AST's pre-commencement inspection finds:

1. A supply diffuser covered with a single layer of poly held by masking tape.
2. Floor poly cut flush at the wall base.
3. A separation wall blocking a marked exit corridor.

The AST does not issue the written notice to proceed, because conditional approval is not allowed (N.J.A.C. 5:23-8.7(a)3). The contractor must:

• Re-seal the diffuser with a two-layer critical barrier.
• Re-lay the floor poly with the 12-inch and 24-inch turn-ups, then hang the wall layer to overlap it by 18 inches.
• Relocate the separation barrier so the required exit stays open.

Only then may the AST approve the start of removal.