MD Asbestos Abatement cheat sheet

Six minerals are regulated as asbestos: chrysotile (serpentine group) and five amphiboles - amosite, crocidolite, anthophyllite, tremolite, and actinolite. Chrysotile accounts for roughly 95% of the asbestos used commercially in the United States.

OSHA counts a fiber as a particle longer than 5 micrometers with a length-to-width ratio of at least 3:1; phase contrast microscopy at roughly 400-450x is the counting method behind the 0.1 f/cc exposure limit.

Friability is the tendency of material to crumble under hand pressure. Friable ACM releases fibers readily; nonfriable material is split into Category I (packings, gaskets, resilient floor coverings, asphalt roofing) and Category II (all other nonfriable ACM).

Core health outcomes are asbestosis (diffuse interstitial fibrosis, strongly dose-related), lung cancer, mesothelioma of the pleura or peritoneum, and nonmalignant pleural effects such as plaques, thickening, and effusion.

Cigarette smoking and asbestos act synergistically: an asbestos worker who smokes faces roughly 50 to 90 times the lung cancer risk of a nonsmoker with no asbestos exposure, while smoking alone does not cause mesothelioma.

Latency is long: asbestosis usually 10-20 years after heavy exposure, lung cancer 15-30 years, and mesothelioma 20-50 years. Disease can follow brief or indirect exposures, which is why take-home and bystander exposure matter.

Amphibole fibers are straight, rigid, and biopersistent in lung tissue; chrysotile fibers are curly, deposit differently, and clear faster. Potency differences drive risk communication and some clearance decisions.

Deposition depends on size: fibers under about 3 micrometers in diameter reach the alveoli, while larger fibers impact in the upper airway and are removed by the mucociliary escalator or by macrophages.

Asbestos is an IARC Group 1 human carcinogen. No threshold has been identified for mesothelioma risk, so all regulated work assumes some residual risk and relies on engineering controls plus respiratory protection.

NESHAP (40 CFR 61 Subpart M) applies to demolition and renovation of facilities with regulated asbestos-containing material. Thresholds that trigger the rule: at least 260 linear feet on pipes, 160 square feet on other components, or 35 cubic feet of RACM removed as debris.

NESHAP requires written notification to EPA or the delegated state agency at least 10 working days before work starts, stating location, quantity of RACM, removal methods, wetting, and the waste disposal site. Ordered demolitions and emergencies have limited exceptions.

NESHAP work practice standards: keep RACM wet, remove it before wrecking, lower rather than drop material, do not use compressed air or grinding, seal waste in leak-tight labeled containers, and produce no visible emissions.

OSHA 29 CFR 1926.1101 covers construction asbestos work and 1910.1001 covers general industry. PEL is 0.1 f/cc as an 8-hour TWA; the excursion limit is 1.0 f/cc averaged over 30 minutes; the action level for the construction standard is 0.1 f/cc TWA.

1926.1101 classes of work: Class I is removal of surfacing ACM and thermal system insulation; Class II is removal of other ACM such as flooring, roofing, siding, and gaskets; Class III is repair where ACM is disturbed; Class IV is cleanup and maintenance activity.

AHERA (40 CFR 763 Subpart E) covers K-12 schools: inspect, maintain a management plan, and use accredited persons for inspection, planning, design, and abatement. The Model Accreditation Plan (Appendix C) sets training requirements adopted by most states.

MAP initial training: worker 4 days (32 hours), supervisor 5 days (40 hours), inspector 3 days, management planner 2 days, project designer 3 days; all disciplines require an annual refresher to stay accredited.

Maryland: the Maryland Department of the Environment administers the asbestos program under COMAR 26.11.21. Abatement contractors must hold a state asbestos contractor license, and workers and supervisors must hold Maryland accreditation cards available on site.

Maryland also requires its own project notification to MDE at least 10 working days before abatement begins, in addition to the federal NESHAP notice. MOSH enforces OSHA-equivalent standards for state and local public employees.

Asbestos work requires HEPA-filtered respiratory protection for all Class I-IV work. Dust masks, surgical masks, and non-HEPA cartridges are prohibited because they do not collect fibers at high efficiency.

Assigned protection factors (29 CFR 1910.134 Table 1): half-mask APR 10; full-facepiece APR 50; half-mask PAPR 50; full-facepiece PAPR 1,000; continuous-flow hood 25; pressure-demand supplied-air respirator or SCBA 1,000 to 10,000.

Select a respirator whose APF keeps the measured or expected exposure at or below the PEL. Where exposure is unknown, start with the highest-protection device available, typically pressure-demand SCBA, until monitoring supports a downgrade.

Fit testing is required before initial use, annually, and after any change affecting fit (weight change, dental work, facial scarring). Quantitative methods (PortaCount, generated aerosol) or qualitative methods (saccharin, Bitrex, irritant smoke) are acceptable.

A clean-shaven face is required wherever the facepiece seals, and eyeglass temple bars may not pass under a full-facepiece seal. A positive- and negative-pressure user seal check is performed at every donning.

Minimum PPE for abatement: disposable coveralls with hood, boot covers, gloves, eye protection, and the assigned respirator. Heavy Class I work commonly uses double coveralls and taped closures.

Street clothing stays in the clean room; disposable suits are HEPA-vacuumed and removed in the dirty decontamination room, then bagged as asbestos waste. Reusable clothing is laundered only by facilities equipped for asbestos.

Respirators are cleaned and disinfected after each use, inspected before donning, and stored sealed. Any respirator that fails a seal check or shows damage is removed from service.

A medical evaluation under 29 CFR 1910.134(e), including a physician-reviewed questionnaire, is completed before fit testing or respirator use. Written procedures belong in the site respiratory protection program.

Containment construction: seal all openings with critical barriers, cover floors with 6-mil poly (often two layers) and walls with 4- to 6-mil poly, and tape all seams. HVAC systems serving the area are shut down and sealed.

Negative pressure: HEPA negative air machines sized for 4 to 12 air changes per hour hold the enclosure at about -0.02 inches of water column relative to adjacent spaces; exhaust is ducted outdoors away from air intakes and windows.

The regulated area is marked with warning signs at every entry reading Danger: Asbestos, Cancer and Lung Disease Hazard, Authorized Personnel Only, and access is limited to trained, accredited workers with a decontamination unit attached.

Wet methods: amended water (water plus surfactant) is applied with low-pressure spray, under about 15 psi, to saturate ACM before and during disturbance. Dry sweeping, compressed air, and high-pressure washing are prohibited.

Removal sequence: work in small sections, keep material wet, lower rather than drop it, and wrap or box it immediately. Glove bags are used for pipe insulation and small tie-ins where a full containment is impractical.

Containment surfaces, tools, and debris are cleaned continuously with HEPA vacuums and wet wiping. Lighting and electrical fixtures are sealed; circuits in wet areas require GFCI protection and asbestos-free covers.

Work practices for flooring and roofing use the same principles: wet, score, pry, or cut with hand tools, avoid sawing or grinding, and package immediately. Mechanical chipping of ACM is prohibited.

Before dismantling containment: complete final cleaning, pass visual inspection, and collect clearance air samples while negative pressure continues. Only then remove poly from clean areas toward dirty areas, bagging it as asbestos waste.

Routine inspection by the competent person includes pressure differential readings, air scrubber function, barrier integrity, worker practices, and a log of daily containment checks.

Standard three-stage decontamination: dirty equipment room, shower, then clean room, arranged so movement is always from contaminated to clean. Large projects add a separate equipment/washroom stage, making four stages.

Exit sequence: HEPA-vacuum the suit, remove outer clothing and boot covers in the dirty room and bag them, shower with soap, then remove, clean, and store the respirator in the clean room. Respirators are not removed inside the containment.

The shower must supply hot and cold potable water, soap, and towels. Showers are required at the end of the shift and before breaks whenever exposures reach or exceed the PEL, and whenever a respirator is worn.

Eating, drinking, smoking, chewing tobacco, and applying cosmetics are prohibited in the regulated area. Hands and face are washed before any break, and no food is stored in contaminated zones.

Street clothes and personal items remain in the clean room. Contaminated clothing is never taken home; coveralls are bagged as asbestos waste or laundered only in an asbestos-equipped laundry.

Footwear is decontaminated or dedicated work boots with boot covers are used, and clean shoes are kept in the clean room to prevent tracking fibers into vehicles and homes.

Decontamination units attach directly to the containment with curtained, overlapping doorways so the pressure gradient always runs from clean to dirty, keeping fibers inside the enclosure.

Phase contrast microscopy (NIOSH 7300/7400) counts all fibers longer than 5 micrometers with a 3:1 aspect ratio. PCM does not identify asbestos type, so non-asbestos fibers can bias results upward.

Sampling train: 25-mm cassette with 0.8-micrometer mixed cellulose ester filter and a 50-mm conductive cowl; typical flow 0.5 to 5 L/min, most often 2 to 2.5 L/min, with the cassette in the worker's breathing zone.

PEL samples are full-shift or consecutive samples that sum to 8 hours; excursion limit samples run 30 minutes. Record pump flow before and after sampling, sample duration, and field notes for every cassette.

Transmission electron microscopy (NIOSH 7402) identifies fiber type and size and is used for AHERA school clearances and other projects with TEM-based criteria.

AHERA clearance: visual inspection, then aggressive air sampling inside containment with TEM analysis; the criterion is 70 or fewer structures per square millimeter.

Aggressive sampling uses a blower or fan directed at containment surfaces to resuspend settled dust before and during sampling, producing a conservative estimate of residual contamination.

A common PCM clearance level is 0.01 f/cc, collected after final cleaning while the enclosure is still under negative pressure. Contract or state criteria may be stricter, so confirm the project specification.

Quality control includes field blanks, sealed cassettes, upwind background samples, chain-of-custody forms, and analysis by an accredited laboratory.

Exposure monitoring is required for each work class where exposures may exceed the PEL; Class I work requires daily monitoring unless a documented negative exposure assessment supports otherwise.

All asbestos waste is kept wet, placed in leak-tight containers (typically 6-mil bags, double-bagged, or sealed drums), and closed before it leaves the regulated area.

Required container label: DANGER: CONTAINS ASBESTOS FIBERS, AVOID CREATING DUST, CANCER AND LUNG DISEASE HAZARD. When waste is not generated at the disposal site, the label also names the generator and the generation location.

NESHAP waste shipment records track generator, transporter, quantity, and disposal site. If confirmation of receipt is not received within 45 days, the generator must contact the disposal site and, if still unresolved, file a report with EPA or the state.

Disposal is limited to landfills permitted to accept asbestos waste. Waste is covered promptly, is not compacted while uncovered, and trucks are tarped with no visible emissions during transport.

Category I nonfriable waste such as floor tile may be shipped in covered, unbagged containers if it stays nonfriable; if it crumbles or is broken, it is handled as regulated friable waste.

Abatement waste includes used poly sheeting, HEPA filters and bags, disposable suits, respirator cartridges, mops, and debris. Decontamination water is filtered before discharge where local rules require it.

In Maryland, waste must go to a landfill permitted by the Department of the Environment, with manifests and disposal records retained and available for inspection. Open burning of asbestos waste is prohibited.

Retain waste shipment records and disposal receipts for at least 2 years as required by NESHAP, and align retention with the project's contract and state record requirements.

Medical exams are provided at no cost, during working hours, within 30 days of assignment, for employees exposed at or above the PEL or excursion limit for 30 or more days per year and for employees required to wear negative-pressure respirators.

Exam content includes work and medical history, a physical examination, a 14-by-17-inch posterior-anterior chest radiograph interpreted by a NIOSH-certified B-reader, and pulmonary function testing; the physician may add other tests.

Periodic exams continue on the schedule the standard and physician require, and an exit exam is offered within 30 days of termination. Employees receive their results and any written opinion on work restrictions.

Exposure records, including air monitoring data and negative exposure assessments, are retained 30 years. Medical records are retained for the duration of employment plus 30 years.

Employees and their designated representatives receive requested exposure and medical records within 15 working days of a written request; the physician's written opinion is provided to the employee.

Training is required initially and annually for all Class I-IV workers. Content covers health effects, work practices, respirator use, decontamination, waste handling, and applicable federal and Maryland rules.

Training documentation records the employee's name, the date of training, and the trainer's identity and qualifications. Maryland accreditation cards are kept on site and available to MDE and MOSH inspectors.

Records are kept in a secure location with controlled access, and confidentiality of medical records is maintained; records are transferred to a successor employer or to NIOSH if the business closes.

A written respiratory protection program, hazard communication labeling and training, and where applicable a written compliance program must be in place and reviewed with each employee before assignment.