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What is Asbestos

Asbestos is a mineral. It is a natural rock mined from the ground in places like Vermont, Canada, and South Africa. Asbestos is not a man-made fiber. (Fiberglass is a man-made fiber.) Asbestos has been used since Roman times. Most recently, it has been used in building materials.

  • Group of naturally occurring minerals
  • Resistant to abrasion, inert to acid and alkaline solutions, and stable at high temperatures. 
  • Widely used in construction and industry 

Types of Asbestos

Asbestos types

There are six types of asbestos minerals. These minerals fall into two groups or classes:

Serpentine

  • Chrysotile “white”- Most common type of asbestos found in the United States

Amphibole

  • Amosite “brown” – best insulator but difficult to control with water
  • Crocidolite – “blue”
  • Anthophyllite, tremolite, actinolite

Properties

  • Asbestos fibers are also virtually indestructible.
  • They are resistant to chemicals and heat.
  • They are very stable in the environment.
  • They do not evaporate into air or dissolve in water.
  • They are not broken down over time.
  • Asbestos is probably the best insulator known to man.

Because asbestos has so many useful properties, it has been used in over 3,000 different products.

Friable vs Nonfriable

Friable – Can be crumbled or reduced to powder by hand pressure.

Non-friable – Can become friable or release fibers if disturbed.

WHAT IS THE PROBLEM WITH ASBESTOS?

  • Working with or disturbing asbestos increases your risk for developing asbestos associated diseases. 
  • No known safe level of asbestos exposure.
  • Asbestos fibers are so small, once released into the air, they may stay suspended there for hours or even days.

HOW HAS ASBESTOS BEEN USED IN THE U.S.?

  • Most products made today do not contain asbestos.
  • Mined since late 1800s
  • More than 5,000 products contain or have contained asbestos.
  • CPSC Ban – patching compounds/fireplaces
  • EPA Asbestos NESHAP rule – TSI & surfacing
  • EPA Ban & Phase Out – banned new uses

EPA Categories – ACBM

  • Surfacing Material – Spray or Trowel Applied
  • Thermal System Insulation – Used to inhibit heat transfer or prevent condensation
  • Miscellaneous Material – Other materials such as floor tile, ceiling tile, roofing felt, concrete pipe, outdoor siding and fabrics

Identifying Asbestos

Asbestos Containing Materials (ACM):

  • Contain greater than 1% asbestos by weight
  • Determined only by bulk sample analysis
  • Must be MDH Certified Asbestos Inspector
  • PLM (polarized light microscopy)

ACM – “Asbestos-containing material,” any material containing >1% asbestos.

PACM – “Presumed asbestos-containing material,”  thermal system insulation and surfacing material found in buildings constructed no later than  1980.

Vermiculite Information

Vermiculite is a naturally-occurring mineral that, when heated to around 1,000 °C, expands and forms pockets of air. This material was then used extensively throughout the US as insulation.

The Vermiculite itself is not a health hazard. However, asbestos minerals were also present at locations where raw vermiculite was mined. This is true of the area around Libby Montana where an estimated 90% of the vermiculite used in the US was produced under the trade name of Zonolite. Zonolite was sold starting in the 1940s and up through the last 1980s.

Although not all vermiculite is the Zonolite brand or contains asbestos, the EPA advises that you should assume that all vermiculite contains asbestos. Zonolite attic insulation, or “ZAI,” may prove harmful to residents because it is present in many attics and walls across the United States and because it is considered “friable”, i.e, easily disturbed and distributed into the air.

Testing Vermiculite

  • Current sampling and analysis (PLM) methods are not accurate for vermiculite. Many States recommend that all vermiculite should be assumed to contain asbestos
  • A new Barium testing method is available but is not recognized by the EPA or State agencies.
    • Barium present in Libby MT mine where WR Grace produced Zonalite (70% of vermiculite sold in U.S. from 1919 to 1990)
    • If the Barium concentration >1500 ppm by ICP analysis then it’s Zonalite and is ACM and deferral required.
    • If <1500 ppm, vermiculite THEN sampled for asbestos content.  Wx can proceed only if none detected.
    • Approximately 90% of samples tested so far have exceeded the action level.
    • Until new method is approved – all vermiculite should be assumed to contain asbestos

WHERE CAN ASBESTOS BE FOUND?

Asbestos-containing roofing products

  •    Asphalt roofing felt
  •    Asphalt roofing shingles
  •    Cement roofing shingles
  •    Roof underlayment
  •    Sealants
  •    Flashing

General Recommendations

EPA and OSHA recommend that asbestos containing materials (ACM) be maintained in good condition.  Only recommend removal when necessary

HOW IS ASBESTOS EXPOSURE CREATED?

  • Friable Asbestos
  • Range in size from .1 to 10 microns in length
  • Very aerodynamic
  • Risks: exposure at work and at home

HOW IS ASBESTOS EXPOSURE CREATED?

The amount of asbestos a worker is exposed to varies according to several factors:

1 – the fiber concentration in the air;

2 – the duration of exposure;

3 – the worker’s breathing rate;

4 – the weather conditions; and

5 – protective equipment

HOW IS ASBESTOS EXPOSURE CREATED?

Everyone has been exposed to asbestos

Everyone will be exposed to more asbestos

AIRBORNE FIBER CONCENTRATIONS

  • Asbestos is known to be hazardous based on studies of high levels of exposure to asbestos workers and laboratory animals.
  • Risks for low level exposure not known so there is no safe level of exposure to asbestos fibers.

AIRBORNE FIBER CONCENTRATIONS

Regulatory Levels

OSHA Permissible Exposure Limit (PEL)

  • f/cc 8 TWA
    • f/cc 30 minute Excursion Limit

Health Effects

Asbestos can kill you. When you work with asbestos, you must work carefully. This information is provided to help workers learn how to protect themselves and others from asbestos fibers.

The more asbestos you are exposed to, the more likely you are to get an asbestos-related disease. All of the asbestos diseases except for mesothelioma are dose-related. Dose-related means the more asbestos you breathe, the more likely you are to get sick. The bigger the dose of asbestos, the more likely you are to get an asbestos-related disease. You may not get sick until years after you breathe the asbestos.

ASBESTOS RELATED DISEASES

Asbestosis:  A chronic lung ailment caused by the build up of scar tissue inside the lungs. Asbestosis can cause shortness of breath, permanent lung damage, and increases the risk of lung infections.

Mesothelioma: Cancer of the lining of the chest cavity lining or abdomen.

Cancers:  Cancer of the lung, esophagus, stomach, colon, and pancreas.

Asbestos Related Diseases:

  • Asbestos causes cancer
  • Long Latency Period – 15 to 40 years
  • Smoking and asbestos exposure
  • Only caused by inhalation

Signs and Symptoms of asbestosis  include:

  • Shortness of breath is the primary symptom
  • A persistent and productive cough (a cough that expels mucus)
  • Chest tightness
  • Chest pain
  • Loss of appetite
  • A dry, crackling sound in the lungs while inhaling.

Your defenses against asbestos

  • Nose – Hair & Mucus
  • Throat – mucus in your throat & coughing
  • Windpipe – Small hair-like follicle (Cilian)
  • White Blood Cells – encase and destroy contaminants

Medical Exams

Medical exams have three parts

  • Work history Questionnaire
  • General physical exam
  • Pulmonary function test (PFT)
  • Additional parts (optional)
    • Chest x-ray
    • EKG
    • Sputum cytology
    • G.I. Hemoccult

Prevention is the only cure

  1. Keep the fibers out of the air and out of your lungs
  2. Avoid Exposure
  3. Quit Smoking
  4. Protective Clothing

SAFE WORK PRACTICES

  • Assume all coating to be asbestos-containing
  • Wet the material before disturbance. 
  • Wear appropriate PPE.
  • Only trained personnel 
  • Minnesota Department of Health Certification

Regulatory agencies include:

  • EPA – Environmental Protection Agency
    • AHERA
    • NESHAP
  • OSHA – Occupational Safety & Health Administration
  • CPSC – Consumer Product Safety Commission
  • DOT – Department of Transportation
  • States
    • NDDOH
    • MDH/MPCA

Prohibited Activities

  1. Use of saws or sanders without HEPA filters
  2. Use of compressed air
  3. No spray application of ACM materials
  4. No employee rotation to achieve lower TWA fiber levels

How to Avoid Asbestos Exposure

If you do not know that a building material is asbestos free…….DO NOT DISTURB IT.

ASBESTOS PROTECTION

Respirator Fit Testing

  • Initially and annually thereafter
  • Qualitative
  • Quantitative
  • Records – 30 years

Respirator Fit Checks

  • Prior to each use
  • Positive pressure
  • Negative pressure

OSHA Classes of Work

Class I Asbestos Work: activities involving the removal of TSI or surfacing ACM and PACM

Class II Asbestos Work: activities involving the removal of ACM which is not TSI or surfacing material. Examples: removal of asbestos-containing wallboard, floor tile, and roofing shingles

Class III Asbestos Work: repair and maintenance operations where ACM and/or PACM is likely to be disturbed

Class IV Asbestos Work: maintenance and custodial activities during which employees contact but do not disturb ACM or PACM and activities to clean up dust, waste and debris resulting from Class I, II, and III activities

Training & Certification Requirements

  • Class I Asbestos Work: 5-day asbestos supervisor training + state certification
  • Class II Asbestos Work:
    • Friable – same as Class I
    • Non-friable – 8-hour material specific training – no certification
  • Class III Asbestos Work: 16 hour O&M training – no certification
  • Class IV Asbestos Work: 2 hour awareness training

Control Options

  1. Removal
  2. Encapsulation
  3. Enclosure
  4. Repair
  5. Operations & Maintenance

Removal

  • Must be performed by certified workers or supervisors
  • Removing the asbestos
  • Thoroughly cleaning and
  • Proper disposal
  • Regulated Area Setup

Encapsulation

  • A Spray of paint-like material on the asbestos
  • Bridging/Penetrating

Enclosure

  • Construction of a rigid, air-tight barrier

Roofing – is it regulated?

Yes, if:

  • Removal renders it friable
  • Use rotary cutting saw  & > 5,580 sq ft

Removal of ACM Roofing & Siding

  • Poly drop cloth
  • Class II Work Activity
  • Removal Methods
  • Keep intact if possible
  • Wet methods when feasible
  • Non – rotary cutting methods
  • Do not drop ACM over 50 feet

Additional Resources