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Bridge Lead Removal and General Site Safety

Personal Protective Equipment

Table of Contents

TYPES OF PROTECTIVE EQUIPMENT

Protective clothing for lead in construction projects usually consists of respiratory protection, disposable coveralls, foot and head covers. Protective clothing does not include street clothes or shoes, T-shirts, blue jeans, sweat bands, or socks. If any of these items are used inside the work area, they should remain there until the job is completed and disposed of as lead-contaminated waste. Other personal protective equipment, such as hearing protection, hard hats, knee pads, eye protection, and safety shoes, that may be used should remain in the work area for the duration of the project. No items should be brought home that have been contaminated with lead.

DONNING PROTECTIVE EQUIPMENT

Protective equipment is put on in the clean room or change area before entering the work area. The following sequence should be used.

1) All street clothes are removed and stored in a clean, convenient location.
2) Clothing and safety shoes that will remain on site are put on, followed by disposable or reusable coveralls.
3) The respiratory equipment is inspected, put on, and fit checked.
4) The hood or head covering is put on over the respirator head straps.
5) When working with caustic paste, rubber gloves must be used and be long enough to protect the lower part of the arm.
6) Other protective equipment, such as safety glasses and hard hat, is put on.

DOFFING PROTECTIVE EQUIPMENT

Whenever a worker or other person leaves a work area for any reason, he/she must go through the decontamination sequence. This sequence should include the following steps:

1) Clean off gross debris using HEPA vacuums inside the work area.
2) Remove all protective garments and equipment (except respirators) in the work area.
3) All disposable clothing should be placed in plastic bags and labeled as lead-contaminated waste.
4) Respiratory protection should then be removed and given a cleaning.
5) Showers are recommended as part of good work practices. In lieu of a shower, workers should as a minimum wash their faces and hands after removing all protective equipment, prior to doing anything. Small amounts of lead on the hands or in the hair may cause serious problems for themselves or their family.

RESPIRATORY PROTECTION

The type of respirator worn by workers depends on the level of exposure. A medical evaluation will be necessary to determine if an individual can wear a particular respirator. Medical conditions, such as heart disease, emphysema, asthma, or other lung disorders, may make it difficult for an individual to wear a particular type of respirator.

There are two major categories of respirators used for work involving exposure to lead: air purifying respirators and supplied air respirators.

Air purifying respirators are commonly called negative pressure respirators. These masks depend on the wearer's lungs to pull air through the filter or cartridge. When a worker inhales, suction is created that draws air outside the respirator into the mask. This suction is referred to as a negative pressure and means that the air pressure inside the mask becomes negative (lower) compared with the air pressure outside e mask when the wearer inhales. In contrast, when a worker exhales or blows out air, a positive (greater) pressure is created inside the mask compared with the outside air pressure.

Facial features can prevent a good respirator seal from occurring with the wearer's face. Facial hair, such as beards, stubble, and sideburns that lie between the sealing surface of the respirator and the face will result in leaks of contaminated air into the mask. Likewise, deformities on the face, such as scars, acne, and lack of teeth, can cause leaks. Because of the potential for leaks through an improper seal, beards and other facial hair that lies along the sealing surface are not permitted for workers who wear respirators, and special care must be given to proper fitting of respirators for workers with facial deformities. Air purifying respirators can only be used in atmospheres with sufficient oxygen and where air contaminants do not exceed the concentration range specified for the respirator.

Below are four sub-categories of air purifying respirators described by the type of face-piece:

• Single use disposable (not recommended for lead work)
• Reusable half-face
• Reusable full-face
• PAPR (powered air purifying respirators), half- or full-face

The PAPR is an improvement over the negative pressure full-face mask but it is not foolproof The protection is only as good as the battery charge and the fit. The batteries are designed to last a full shift, but then require a full 8-hour charge. PAPR units come with a small flow meter that enables the worker to test the air flow. A problem with Nicad batteries is that, when the charge gets low on them, it tends to die quickly rather than slowly. When the charge gets too low the motors will simply stop running. Another limitation of PAPRs is that, under heavy work conditions, a worker can use more air than the PAPR provides. Negative pressure conditions are created when this happens. It is called "overbreathing" a PAPR.

• Cartridge life problem. The cartridge has only so much capacity, and when that capacity is reached, the cartridge is no longer any good. If the cartridge is used for organic vapors or gases and the capacity is reached, the contaminants will pass through the filtering material directly into the worker's lung. This is called "breakthrough." Some chemicals have poor warning properties so the worker will not smell the chemical when breakthrough occurs. This will cause serious problems. As a result, this type of respirator cannot be used with substances that have poor warning properties.

  If the contaminant is a solid, and a HEPA or other particulate filter is used, at some point the worker will have a hard time breathing through the filter as it becomes clogged. It will need to be changed at that point.

• Oxygen limitations. Air purifying respirators can only be used when there is sufficient oxygen in the air. The minimum concentration must be no less than 19.5 percent.

• IDLH concentrations (immediately dangerous to life or health). Under these concentrations it is much too dangerous to trust this type of respirator. It doesn't provide enough margin of safety.

Limitations of Supplied Air Respirators

• The air line impairs worker movement. The air line cannot exceed 300 feet (91.4M) in length according to regulations. Workers also must retrace their steps coming off of the job.
• The air line is vulnerable to damage. Rough or sharp surfaces can puncture the line. The rubber hose may deteriorate from exposure to chemicals or to sunlight. Falling objects, vehicles, and heavy equipment also can damage the air line.
• The system air compressor must be located away from potential chemical or contamination hazards.
• All filters and alarms must be working properly and the system must be maintained according to the manufacturers' recommendations.
• The maximum inlet pressure cannot exceed 125 psi (862kPa) or fall below 80 psi (522kPa).

There are supplied airline masks which include an escape SCBA (self-contained breathing apparatus) tank. A small tank contains a 5 to 10 minute air supply. When this back-up tank is provided, workers can be assigned to enter almost any area no matter what the concentration of contaminant in the air.

INSPECTION OF HALF- AND FULL-FACE RESPIRATORS

A complete inspection of the respirator should be done before each use. The general inspection procedure is as follows. Parts from different manufacturers may not be interchanged!

• Check general appearance (no deformities).
• Check the harness strapping for tears or loss of elasticity.
• Check inhalation valves for tears, distortions, and debris.
• Check the exhalation valve, and valve seats, for moisture, tears, distortions, and debris. The valve should not be stiff. Grab the rubber stem from inside the respirator and twirl it gently. The exhalation valve should move freely. Make sure the cap is on the exhalation valve. If the exhalation valve fails, there is nothing between you and the contaminated air.
• Check that gaskets are present where the filters screw in. Some respirators do not have gaskets.

• Remove the filters.
• Wash rubber face-piece in a detergent solution.
• Rinse completely in clean warm water.
• Air dry in clean area.
• Do not put respirator together when wet.
• When dry, reassemble and store in a clean plastic bag.

GENERAL RESPIRATOR USE

Respirators need to be selected and adjusted each time they are put on to ensure the best possible seal. How is a worker to know when a mask is providing a satisfactory seal? Respirators will not seal properly when there is facial hair between the respirator seal and the skin. You must be clean shaven.

Workers assigned to wear negative pressure respirators under the OSHA Lead Standard for Construction must have a qualitative fit test before the worker begins using the respirator for work and then every 6 months after that. The qualitative fit test can only be used for testing the fit of half-face negative pressure respirators.

According to OSHA, for full-face negative pressure respirators, only the quantitative fit test can be used for fit determination.

Positive Pressure Fit Check

• Put the respirator on and tighten by adjusting the straps.
• Gently cover the outlet covering of the exhalation valve with the palm of the hand.
• Gently exhale and hold your breath for 10 seconds. If the face-piece bulges slightly and no leakage of air out of the face-piece is detected, the respirator face seal and inhalation valve are working.

Negative-Pressure Fit Check

• Put on respirator and tighten adjusting straps.
• Cover the inlet opening(s) of the respirator cartridge(s) with the palm of the hand(s). Apply a minimum amount of hand pressure to the cartridges so as not to affect the respirator face seal.
• Inhale gently and hold breath for 10 seconds. If the face-piece collapses slightly and no leakage of air into the face-piece is detected, the seal is acceptable. If not, readjust and repeat procedure

The order in which the negative and positive fit test are done does not matter.

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