Asbestos is fibrous form of mineral silicates belonging to serpentine & Amphibole groups of rock forming minerals, including Amocites ( brown asbestos), Crocidolite (blue asbestos), Chrysotile ( white asbestos), Tremolite, Actinolite,Anthophyllite or any mixture containing one or more of these.
Asbestos has been used in literally thousands of products. Collectively these are frequently referred to as asbestos-containing material (ACM). Because of its unique properties—fire resistance, high tensile strength, poor heat and electrical conductivity, and being generally impervious to chemical attacks –asbestos proves well-suited for many uses in different industries.
One of the most common uses for asbestos has been as a fireproofing material. They vary in color from white to dark gray; occasionally they have been painted or encapsulated with a clear or colored sealant.
Asbestos has also been added to asphalt, vinly and other materials to make products like roofing felts, exterior siding, floor tile, joint compounds and adhesives.
As an insulator, asbestos received widespread use for thermal insulation and condensation control. It was usually spray applied, trowel applied or factory installed on or within equipment. Asbestos proved valuable as a component of acoustical plaster.
Environmental Protection Agency (EPA) identifies three categories of ACM
The adverse health effects associated with asbestos exposure have been extensively studied for many years. The inhalation of asbestos fibers may lead to increased risk of developing one or more diseases (Asbestosis, Lung Cancer, Mesothelioma). Exactly why some people develop these diseases and others do not remain a mystery.
It is important to recognize that the majority of people who have died as a result of asbestos exposure were workers who worked with raw or processed asbestos. These workers were frequently exposed to high concentrations of asbestos fibers each working day with little or no protection. As of today we follow specific work practices and wear appropriate protection, including respirators, to minimize the risk of exposure.
Asbestos related diseases are not simply a result of the presence of asbestos. In general, a substance must enter the body in order to produce the disease associated with that substance. The two major routes of entry into the body:
Inhalation – Breathing is the primary mode by which asbestos enters the body. Incredibly small air borne asbestos fibers, invisible to the naked eye, are easily inhaled. These inhaled fibers can directly affect the respiratory system.
Ingestion – Swallowing is a secondary mode by which asbestos enters the body. Asbestos fibers which enter the lung may be either coughed up or removed from the lung in a natural cleaning mechanism which deposits the fibers in mucous, which is then swallowed. The fibers may be ingested by a worker eating in a room contaminated by asbestos, drinking asbestos contaminated water, or by the worker failing to clean his/her hand prior to eating.
Prolonged exposure to asbestos material, unprotected, may produce irritation, asbestos warts or corns on the surface of the skin, but the fibers will not be absorbed through the skin.
OSHA has issued a PEL for asbestos. The permissible exposure limit is defined as the concentration that OSHA will allow a worker to breathe before requiring respiratory protection. Currently the PEL for asbestos is 0.1 f/cc or 1, 00,000 fibers per 8 hour shift. These limits are expressed for exposure durations – usually an 8 hour or full work shift. This means a worker can be exposed to asbestos dust at a concentration of 0.1 f/cc over an 8 hour Time Weighted Average (TWA) without being required by OSHA to wear a respirator. If the concentration goes above the PEL then the worker must begin wearing respiratory protection.
According to OSHA, if the concentration in the work area goes above 0.1 f/cc (Fibers/cubic centimeter) you must begin respiratory protection. If the concentration inside the respirator goes above 0.1 f/cc you are required to use better level of protection to maintain your exposure inside the respirator below PEL. Please refer below table for OSHA respiratory protection requirements.
|Protection Factor (PF)||Outside Airborne Level||Required Respirator|
|10||Not in excess of 1 f/cc
(0.1 f/cc x 10= 1 f/cc)
|Half Face- air purifying with
|50||Not in excess of 5 f/cc
(0.1 f/cc x 50= 5 f/cc)
|Full Face- air purifying with
|1000||Not in excess of 100 f/cc
(0.1 f/cc x 1000= 100 f/cc)
|Powered air purifying
|1000||Not in excess of 100 f/cc
(0.1 f/cc x 1000= 100 f/cc)
|Type C – Supplied Air|
|10000||Not in excess of 1000 f/cc
(0.1 f/cc x 10000= 1000 f/cc)
|Self Contained Breathing
Protective clothing and items such as coveralls (disposable), hard hats, gloves and safety shoes should remain in the work area for the duration of the project. It is insured to provide the employees (workers dealing with asbestos) eye, head, foot and hand protection in accordance with OSHA standards 29 CFR 1910.133, 1910.135, 1910.136 and 1910.138 respectively.
To summarize, below is a list of items normally worn by asbestos abatement workers:
Work classification (as per OSHA)
Class I: Means activities involve the removal of thermal system insulation (TSI) and surfacing ACM or PACM (presumed asbestos containing material).
Class II: Means activities involving the removal of ACM which is not TSI or surfacing materials. This includes but is not limited to ACM wallboard, floor tile and sheeting, ceiling tiles, roofing, siding shingles and construction mastics.
Class III:Means repair and maintenance operations where ACM including TSI and surfacing is likely to be disturbed.
Class IV: Means maintenance and custodial activities during which employees contact ACM and PACM and activities to clean up waste or debris containing ACM & PACM.
Projects are categorized as minor, small or large. (As per EPA)
Minor Projects: Less than or equal to 10 square feet (ft²) or less than or equal to 25 linear feet (ft).
Small Projects: Between 10 and 160 square feet or between 25 and 260 linear feet.
Large Projects: 160 square feet or greater or 260 linear feet or greater
EPA regulations which cover the removal of asbestos material require wetting the material before the removal begins and keeping it wet as it is removed, bagged, transported and disposed of. Two advantages to the use of wet methods for removing asbestos materials include a reduction in air borne fiber concentrations which are generated during removal and a reduction in the effort required to remove the material. The wetting agent (i.e. surfactant) is a combination of chemicals which aids in penetration of water into the material and increases the probability of individual fiber wetting.
At this point of abatement project the work area is to be sealed off with two layer of 6mil fire retardant polyethylene on the floors and two layer of retardant polyethylene on walls & critical barriers should be covered with at least 2 independent layers of 6mil fire retardant polyethylene in a way that floor extends the wall and wall extends the floor . The decontamination unit and negative air filtration units are in place. The first step in the removal process is to thoroughly wet the ceiling material with a low pressure mist of amended water. Time should be allotted between spraying with amended water and removal to provide maximum penetration into the material.
Decontamination unit for smaller projects
|Clean Room||Shower||Equipment Room||Work Area|
Decontamination Unit for large projects
|Clean Room||Air Lock||Shower||Air Lock||Equipment Room||Work Area|
There is a wide variation in the types of asbestos containing thermal system insulation used on pipes, boilers and tanks. Pipes may be insulated with preformed fibrous wrapping, corrugated paper, and a chalky mixture containing magnesia, fiber felt & insulating cement. Usually a protective jacket, which may also contain asbestos, made of paper, tape, cloth, metal, or cement covers the insulation materials. Boilers and tanks may be insulated with asbestos “blankets” on wire lath, preformed block or the chalky magnesia mixture which is typically covered with finishing cement. Careful handling & packaging is required in many cases because of the metal jackets, bands, or wire associated with the insulation materials. Glovebags which can be sealed around sections of pipe to form “mini-containment areas” may be used in some situations for removing pipe insulation. In some cases Tent procedure with the attached decon can be used to remove the pipe insulation. Insulated objects which are not readily accessible or are too large or hot for application of the glovebag technique, may require a full area enclosure with modified removal techniques.
Air sampling plays an important role in asbestos industry since it is a method by which one determines the quality of air or more specifically the asbestos concentration in the air.
OSHA sampling is the only form of air monitoring which is required inside the abatement work area during the actual abatement process. OSHA sampling measures the air that each worker breathes during the work shift to determine the fiber concentrations to which they may be exposed. High fiber counts may require increased levels of respiratory protection.
Area sampling establishes the asbestos levels before, during and after removal, both inside and outside the work area and outside the building near the load out area.
Air samples collected prior to an abatement to determine the fiber concentrations which occur naturally in the air. It is important to determine what the natural fiber concentration is before the work begins because this concentration should not be exceeded during the abatement or at final clearance.
Air samples collected during the abatement document fiber concentrations to determine adequate engineering controls and to maintain barriers in order to prevent the release of the fibers.
Final clearance samplings are done at the completion of the abatement activities, but before all barriers are taken down. This sampling helps to determine if the asbestos is removed and the area is cleaned properly.
Pumps are the backbone of the air sampling process, providing the means by which air is drawn through the filter that is housed in the cassette. Sampling pumps are typically categorized as either high volume (electric) or low volume (personal) pumps, which are usually battery powered. High volume pumps draw anywhere from 5 to 30 liters of air per minute (LPM) while low volume pumps typically draw from 0.5 to 5 LPM. High volume pumps are usually utilized for area sampling.
Once quite popular for applications such as final clearance air monitoring by Transmission electron Microscopy (TEM), polycarbonate filters should be used with caution and are being used less frequently because of fears of fiber loss from the smooth filter surface during sample handling & transport. TEM is a test where in we get to know about the presence of asbestos fibers.
When setting up air sampling pumps, they are not placed near walls, corners, air currents, or where they may influence each other. Once the pumps are in place, the location, time (24-hr clock), date, sample numbers, pump number, flow rate, employee’s initials and other related information, is recorded.
The air cassette is independent of the pump motor. The cassette is angled 45 degrees downward from the stand. This is to ensure that no asbestos will drop into the cassette while sampling. Once the pumps are set, the end cap is removed from the cassette, the pump is to be turned on and let it run for the correct amount of time. The flow rate can be set as desired by Rota meter. Total volume of air collected will be approximately 1200- 1300 liters. Later the cassettes are sent to authorized lab for testing by TEM method.
So finally asbestos project get completed in 2 phases
Phase I –
A) Survey ,Planning & Design
( complete report submission along with chain of custody)
B) Back Ground Air sampling
Phase II –
A) Work Area Preparation
B) Gross removal.
C)Final clean Up, Final clearance.(with post removal air sampling)
D) Waste disposal.
Sun silica glass nettings are used as a filtering material in metallurgy and in aerospace, marine, and molten metal, power and other industries as well.
Sun silica glass fibre fabrics are an excellent alternative to asbestos.
Sun Silica fabric are defined by the Low Smoke
Emission, Sun Melting Point, Drapability, Water repellence, versatility and fireproof
Our uses a special E- Glass fabric with over 76% Silica & Aluminum Oxide (Al2O3) – 3.5 +/- 0.5% in it for the production of Sun Silica fabric. A soft acid is used to leach the fabric. The leeching is also done to obtain just about 95-96% Silica content in the fabric.
The minimal leaching done on the Our’s Sun Silica fabric using a ‘soft’ acid results in Sun tensile strength of the fabric.
The other major advantage is the low shrinkage factor of just about 1.5% with Our’s Sun Silica fabric compared to the shrinkage of standard of Silica Fabric which is not less than 7%.
Most of the other manufacturers use a normal E – Glass fabric with about 55% Silica content and leach it using a strong acid like Hydrochloric Acid ( HCl) to obtain a 98% – 99% Silica rich fabric. This strong acid attack weakens the fabric, thereby reducing the tensile strength to a large extent. A microscopic study of the silica fibre strand also shows a very rough surface after the acid action on the yarn surface. A very Sun temperature resistance is also not possible and fabric is seen to be brittle to a large extent.
These factors exhibit the advantage of Our’s Sun Silica fabric with 96% Silica over the conventional 99% of silica fabrics. The Combination of silica (SiO2) and Aluminum acid (Al2O3) has rendered the fabric more fire resistant. The superior technology and production is the reason for the Our’s Sun Silica Fabric to be accepted by the government in USA for defence applications as well as for many critical application areas in Japan.
We offer Insulation Jackets & Pads to our clients. Manufactured using high grade raw material, the range also.
In order to meet the diverse requirements of our reputed clients, we are manufacture and supply