Reducing Respiratory Hazards during Asbestos Sampling

Asbestos refers to a set of six naturally occurring fibrous minerals with six primary sub-classifications:

  • Chrysotile
  • Crocidolite
  • Amosite
  • Anthophyllite
  • Tremolite
  • Actinolite

About 95% of the asbestos in commercial use in the United States is chrysotile.

Although microscopic in size, asbestos fibers are extremely durable and resistant to fire and most chemical reaction.

Because of these characteristics, asbestos has been used in a variety of manufactured goods including:

  • Building materials (roofing shingles, ceiling and floor tiles, paper products, insulation and acoustical products, and asbestos cement products)
  • Friction products (automobile clutch, brake, and transmission parts)
  • Heat-resistant fabrics, packaging, gaskets, and coatings

Improper attempts to remove asbestos-containing materials may release asbestos fibers into the air, increasing asbestos levels and endangering people living or working in the exposed area.

Elevated concentrations of airborne asbestos may also occur when older buildings are demolished or renovated, or when older asbestos-containing materials begin to break down. In any of these situations, asbestos fibers tend to create tiny particles that float in the air.

Negative health effects

Studies on both people and laboratory animals have shown that asbestos can increase the risk for some types of cancer.

When asbestos fibers in the air are inhaled, some may reach the ends of the small airways in the lungs or penetrate into the outer lining of the lung and chest wall.

The photo to the left shows a microscopic view of a lung with embedded asbestos fibers.

When this occurs, these fibers may irritate the cells in the lung and eventually cause lung cancer or mesothelioma.

Most cases of lung cancer occur 15 or more years after initial exposure to asbestos. For mesothelioma the time between initial exposure and mesothelioma occurs after 30 years or more.

A more common health risk of asbestos exposure is a lung disease known as asbestosis.

Asbestosis develops after a person breathes high levels of asbestos over time and some of the fibers embed deep into the lungs.

Irritation caused by the fibers eventually leads to lung scarring. While some people may not have serious symptoms, others may be seriously disabled by breathing problems.

Workplace Regulations

In the past, the use of asbestos was widespread. Although now heavily regulated, asbestos is still found in older buildings or materials.

Because asbestos particles are invisible to the human eye, many regulating authorities require sample tests to be conducted before renovations, demolition or any other type of disturbance is done to a structure.

The Occupational Safety and Health Administration (OSHA) has the following three standards to protect workers from exposure to asbestos in the workplace:

  • 29 CFR 1926.1101 covers construction work, including alteration, repair, renovation, and demolition of structures containing asbestos.
  • 29 CFR 1915.1001 covers asbestos exposure during work in shipyards.
  • 29 CFR 1910.1001 applies to asbestos exposure in general industry, such as exposure during brake and clutch repair, custodial work, and manufacture of asbestos-containing products

In addition, the National Emission Standards for Hazards Air Pollutants (NESHAP) requires the owner of a building or the operator to notify appropriate state agencies before any demolition, or before any renovations of buildings that could contain a certain threshold amount of asbestos or asbestos-containing material.

Sampling Methods

There are different types of sample tests that may be performed to determine if asbestos fibers are present, two in particular are Phase Contrast Microscopy (PCM) and Transmission Electron Microscopy (TEM):

  • PCM is widely used to measure fiber concentrations of air samples. This is routinely done at asbestos abatement sites and can be applied for environmental monitoring, personnel monitoring, and clearance testing for minor abatement projects.
  • TEM represents the most sophisticated technology available for characterizing asbestos minerals. This technique is now the standard for most airborne investigations including post abatement clearance testing, as well as diagnostic and environmental monitoring activities.

Due to the uncertainty of whether a sample will test positive or negative for asbestos, it is vital that test technicians utilize respiratory safety mechanisms during testing.

Benchtop, modular solutions for asbestos sampling

Sentry Air Systems offers asbestos-containment, negative pressure units equipped with either ULPA or HEPA filter media. ULPA filters are up to 99.9995% efficient for 0.12 microns and larger, and HEPA filters are up to 99.97% efficient on particles 0.3 microns or larger.

This Model 300 Winged Sentry is a benchtop fume extraction unit offering horizontal airflow up to 350 CFM.

The adjustable “wing flaps” assist in directing the asbestos-contaminated air towards the unit’s inlet and into the filter chamber while the operator works between the wings.

This system features a custom clear, hinged acrylic lid with microscope lens cutout for even further containment.

This 30-inch Wide Ductless Fume Hood combines powerful air flow with a sturdy and compact enclosure for optimal respiratory protection.

Designed to pull harmful asbestos fibers and dust away from the operator’s breathing zone and into the filter chamber, this unit has an inlet velocity of up to 200 FPM.*

In addition, the hood features a custom clear, hinged acrylic lid with microscope lens cutout and clear, anti-static vinyl curtains for increased asbestos containment.

*With variable speed control, varies with curtain and filter media.

Contact Sentry Air

For more information on respiratory protection during asbestos sampling, contact Sentry Air Systems at 800.799.4609, email visit our website or fill out the feedback form below.