Asbestos

Engineering, Management and Control

Kenneth F. Cherry

• Publisher: CRC Press
• Year: 2020
• Topic: Technology & Engineering
• eBook ISBN:
  9781000157635
• Subtopic: Occupational & Industrial Medicine
• Index: Technology & Engineering

This single source asbestos reference/text book incorporates major legal issues and cost estimating methods. Every aspect of abatement work from initial survey through final cleanup is detailed. In addition, medical aspects, respirator use, training, sample contracts and other topics, coupled with a practical approach, make this the book to have when the goal is to get the job done. The book contains lots of valuable information and data, including CFR 1910 and NFPA 220/241, and will serve as an ideal reference source for asbestos contractors, building owners, industrial hygienists, consultants, and schools.

1

Current Uses of Asbestos

United States asbestos consumption has been declining for years because of increased restrictions and lawsuits by victims of lung cancer and other diseases. Consumption in 1985 was 155,500 metric tons, down from 226,000 in 1984 and 349,000 in 1981, according to the U.S. Bureau of Mines.¹

The chemical process industries have gradually switched to substitutes over the years. Asbestos was long ago replaced by such materials as fiberglass and polyurethane in insulation. One area where asbestos is still widely employed is that of gaskets and packings, although a variety of substitutes is now available.

Many states have adopted an information standard for postasbestos abatement of 0.01 total fibers per cubic centimeter (f/cm³) or less as the air quality level to be attained before the asbestos removal work area can be reoccupied. This standard is based on phase-contrast microscopy, P CAM-239 or NIOSH 7400 (see Appendix to OSHA Part 1910 Asbestos Standard).

European countries generally have their own workplace standards for asbestos exposure, but those in the European community must also comply with a directive of 0.1 mg/m³.

West Germany has complex regulations for the control of asbestos, and a cooperative government/industry program that began in 1981 with the goals of developing substitute materials and eventually phasing out asbestos. Roughly 70% of the asbestos used in Western Europe is reportedly used for reinforcing cement in construction.¹

Japan’s asbestos consumption nose-dived from 100,000 metric tons in fiscal 1980 to 55,000 metric tons in fiscal 1985. The Ministry of International Trade and Industry attributes this to a switch to such substitutes as corrugated metal sheets for roof tiles, and fiberglass in general for housing applications.

A problem in replacing asbestos in building materials relates to fiber strength. Asbestos-cement test sheets show a strength of 30 mega pascal (MPa), compared to 27 for glass, 25 for polyacrylonitrile, 22 for polypropylene, 20 for cellulose, 17 for polyvinyl acetate (PVA), and 17 for other mineral fibers.

Finding materials with a mechanical strength comparable to that of asbestos is difficult. Some replacements include flexible graphite, carbon and graphite yarn, glass fibers, aramid, polybenzimidazole (PBI), polytetrafluoroethylene (PTFE), ceramics, mica, and various metals.

No single material matches asbestos’s strength, chemical resistance, and flexibility over a wide temperature range. Equal or superior properties may be obtained, however, by combining two or three materials.

Asbestos still has well over 50% of the packing and gasket market, compared to the traditional 80-90%. Pipe flanges are the biggest application for sealing material in chemical process plants, the others being valves, pumps, compressors, and pressure vessels. Users are reluctant to change to costlier materials with which they have had no experience. Flexible graphite can withstand temperatures of more than 5000°F (compared with about 1200°F for asbestos), say suppliers, while cautioning that it is limited to about 750-850°F in the presence of oxygen and to around 1200°F in steam.

Flexible graphite, developed about 20 years ago, was little used until recently because it costs too much. Now it has around 5–10% of the packing market. One drawback is that graphite, an electrical conductor, can enhance galvanic corrosion in steel.

In the gasket area, chlorite/graphite sheet, on the market since 1983, is the most popular nonasbestos filler for spiral-wound gaskets. In compressed gaskets—conventional asbestos encapsulated in a rubber binder—aramid, glass fibers, and mica are being used as reinforcement, while such materials as talc, barium sulfate, clay, and mica are fillers.²

SUMMARY OF OSHA PART 1910

The following is a brief summary of OSHA asbestos rules. It is provided to assist in explaining these regulations to nonexperts. A more complete section for technical use is provided in Chapter 9 of this book.

A. Permissible Exposure Limit (PEL)

No employee is to be exposed to airborne concentrations of asbestos in excess of 0.2 f/cm³ of air as an 8-hr time-weighted average (TWA).

B. Monitoring

1. Every employer shall perform initial monitoring on employees who are or may be exposed at or above the action level (0.1 f/cm³).

2. The employer may rely on objective data that demonstrates that asbestos is not capable of being released in concentrations in excess of the action level in lieu of sampling.

3. Monitoring is to be repeated at least every six months for employees whose exposures may reasonably be foreseen to exceed the action level.

4. All samples taken to satisfy the monitoring requirements shall be personal samples.

5. The employer is required to notify the affected employees of the results of the monitoring within 15 days of the receipt of the results. This must be done in writing.

C. Regulated Areas

1. The employer is required to establish regulated areas wherever airborne concentrations of asbestos exceed the permissible exposure limit.

2. These regulated areas must be demarcated in any manner that minimizes the number of persons who will be exposed to asbestos.

3. Access to regulated areas is limited to authorized persons.

4. Each person entering a regulated area shall be provided and required to use a respirator.

5. Eating, drinking, smoking, the chewing of tobacco or gum, and the application of cosmetics is prohibited in the regulated area.

D. Methods of Compliance

1. The employer is required to institute engineering and work practice controls to reduce and maintain exposures to or below the PEL.

2. All hand-operated and power-operated tools which would produce or release fibers of asbestos must be provided with local exhaust ventilation.

3. Where practical, asbestos is to be handled, mixed, applied, removed, or otherwise worked in a wet state.

4. Materials containing asbestos shall not be applied by spray methods.

5. Compressed air is not to be used to remove asbestos unless it is used in conjunction with a ventilation system.

E. Compliance Program

1. Where the PEL is exceeded, the employer is required to establish and implement a written program to reduce employee exposures to or below the PEL.

2. The employer shall not use employee rotation as a means of compliance with the PEL.

F. Respiratory Protection

1. The employer is required to provide and ensure the use of respirators where required.

2. Appropriate respirators are to be provided at no cost to the employees.

3. Power air-purifying respirators (PAPRs) are to be provided if an employee chooses to use this type and it provides adequate protection.

4. Where respirators are required, a written respirator program shall be instituted.

5. Employees who use filter respirators are to be permitted to change filters whenever an increase in breathing resistance is detected.

6. Employees who wear respirators are to be allowed to leave the regulated area whenever necessary to wash their faces and respirator facepieces to prevent skin irritation.

7. Employees shall not be assigned to tasks which require the use of respirators if an examining physician determines that the employee will be unable to function normally wearing a respirator.

8. Quantitative or qualitative fit tests shall be performed on employees wearing negative-pressure respirators at the time of initial fitting and at least every six months thereafter.

G. Protective Work Clothing and Equipment

1. Where employees are exposed to asbestos above the PEL, the employer is required to provide to employees, at no cost, appropriate protective work clothing and equipment.

2. The employer shall ensure that work clothing contaminated with asbestos is removed only in the change rooms provided.

3. Employees are not permitted to remove contaminated work clothing from the change room.

4. Contaminated work clothing shall be stored in closed containers.

5. Containers of contaminated protective equipment or work clothing are to be properly labeled.

6. Clean protective clothing is to be provided at least weekly to each affected employee.

H. Hygiene Facilities

1. The employer is required to provide clean change rooms for employees who are exposed to asbestos in excess of the PEL.

2. Employees who are exposed to asbestos in excess of the PEL are required to shower at the end of the shift.

3. The employer must provide a positive-pressure filtered-air lunch room for employees whose asbestos exposure exceeds the PEL.

I. Communication of Hazards

1. Warning signs shall be provided and displayed at each regulated area.

2. Warning labels complying with 1910.1200 shall be affixed to all asbestos-containing materials.

3. Employers who manufacture asbestos products are required to develop Material Safety Data Sheets complying with 1910.1200.

4. The employer is required to institute a training program for employees who are exposed to airborne concentrations of asbestos at or above the action level.

J. Housekeeping

1. All surfaces shall be maintained as free as practicable from accumulations of asbestos.

2. Surfaces are not to be cleaned by the use of compressed air.

K. Medical Surveillance

1. The employer must institute a medical surveillance program for employees who are or may be exposed to asbestos at or above the action level.

2. Before an employee is assigned to a job exposed to asbestos, a preplacement medical exam shall be provided.

3. Periodic medical exams a...

Table of contents

• Cover
• Title Page
• Copyright Page
• Dedication
• Preface
• Table of Contents
• 1 Current Uses of Asbestos
• 2 Engineering Aspects
• 3 Establishing an Operation and Maintenance Program for Asbestos
• 4 The Building Survey
• 5 The Contractor’s View of a Project
• 6 Sample Specifications
• 7 Work Practices for Removal Projects
• 8 Health and Safety
• 9 Regulations
• 10 Cost Estimating
• 11 Legal Aspects and Insurance
• 12 Asbestos Hazard Emergency Response Act
• Glossary
• Appendix A Substitutes for Asbestos Materials
• Appendix B Asbestos Information Sources
• Appendix C AHERA Training Requirements
• Appendix D Typical Equipment Costs Based on 1987 Catalog Prices
• Bibliography
• Index