Crystalline Silica Air Monitoring, Dust Testing and Industrial Hygiene Consulting
Independent respirable crystalline silica air testing, employee exposure monitoring, area and perimeter sampling, settled-dust testing, construction-dust migration assessments, baseline monitoring and written industrial hygiene reports throughout NYC, Long Island, Westchester, nearby New Jersey and southern Connecticut.
Start with the question the sample must answer
Personal breathing-zone, fixed-location air and settled-dust samples measure different things. Selecting the correct sample type before work begins is important because the results cannot be treated as interchangeable after collection.
Use personal breathing-zone monitoring when the question is what a worker is exposed to while performing representative tasks during the monitored period.
Best fit:Use fixed-location air sampling when the question involves a selected room, perimeter, occupied area, containment boundary or suspected dust-migration pathway.
Best fit:Use settled-dust sampling when the question is whether crystalline silica is present in deposited dust on selected surfaces after construction, renovation, cutting or migration.
Best fit:Independent silica and construction-dust assessment
Angstrom Testing Services LLC provides respirable crystalline silica air monitoring, employee exposure assessment, area and perimeter sampling, settled-dust testing, baseline monitoring, construction-dust migration assessment, industrial hygiene consulting, and written reporting for residential, commercial, institutional, construction, transit, infrastructure, manufacturing, and public-sector projects.
Silica concerns may involve concrete cutting, coring, drilling, grinding, chipping, jackhammering, demolition, façade work, brick and block disturbance, mortar removal, repointing, stone fabrication, countertop cutting, tile work, abrasive blasting, tunneling, road work, masonry, cementitious products, and other silica-containing materials.
The correct sampling approach depends on the question being asked. Personal breathing-zone monitoring is used to evaluate employee exposure. Area and perimeter sampling can document selected locations outside the worker’s breathing zone. Settled-dust testing can help characterize dust deposited on selected surfaces. These sample types are related, but they are not interchangeable.
Angstrom provides independent inspection, testing, sampling, laboratory coordination, consulting, and reporting. We do not perform construction, demolition, concrete cutting, dust cleanup, remediation, abatement, or restoration contracting.
Common project conditions
Wall saws, slab saws, handheld saws, core drills, floor grinders, scarifiers, chipping tools, and jackhammers can generate respirable silica-containing dust.
Brick cutting, block work, mortar removal, repointing, tuckpointing, façade restoration, stone work, and demolition may require exposure or area monitoring.
Cutting, grinding, polishing, finishing, installation, and repair of quartz-rich engineered stone can generate high concentrations of respirable crystalline silica.
Personal breathing-zone samples may be used to evaluate representative workers, tasks, shifts, tools, materials, controls, and respiratory-protection decisions.
Construction dust may enter apartments, offices, corridors, stairwells, neighboring units, common areas, HVAC systems, or other spaces outside the work zone.
Pre-work, upwind, background, perimeter, adjacent-area, or continuous project monitoring may support transit, infrastructure, façade, demolition, and public projects.
Selected surface samples may help document whether crystalline silica is present in dust deposited after cutting, demolition, masonry work, or uncontrolled migration.
Owners, employers, contractors, unions, attorneys, insurers, agencies, and facility managers may need independent sampling methods, laboratory results, and written interpretation.
Air, dust and industrial hygiene services
Sampling is selected for the employee, task, location, project phase, material, particle-size fraction, regulatory objective, analytical sensitivity, and intended use.
A respirable size-selective sampler is positioned in the worker’s breathing zone to evaluate exposure during representative tasks or work periods.
Compare personal, area and settled-dust samplingSampling may be designed to represent an eight-hour time-weighted average or another work period appropriate to the exposure-assessment objective.
Shorter-duration samples may document selected high-dust activities, tool use, material disturbance, control performance, or task-specific exposure patterns.
Fixed-location samples may be collected inside or outside work zones, near occupied areas, at boundaries, or along suspected migration pathways.
Monitoring may document selected locations around containment, building perimeters, neighboring spaces, public areas, or sensitive receptors.
Pre-construction or pre-disturbance samples may characterize selected background conditions before transit, utility, façade, demolition, or infrastructure work.
Dust samples may be collected from documented surface areas to identify or quantify crystalline silica in selected deposited dust.
Inspection, pathway review, containment observations, particle screening, area sampling, and settled-dust testing may be combined.
Sampling may support review of local exhaust, vacuum shrouds, wet methods, isolation, housekeeping, HEPA filtration, and work-practice controls.
Respirable crystalline silica samples may be analyzed by X-ray diffraction for quartz, cristobalite, and tridymite using NIOSH Method 7500 or another suitable method.
Direct-reading particle instruments may help document timing and dust patterns, but they do not identify the crystalline-silica content of the particles.
Reports may include tasks, workers, controls, flow rates, durations, sample volumes, laboratory results, interpretation, limitations, and recommended next steps.
Quartz, cristobalite and tridymite
Crystalline silica is a mineral constituent of many natural and manufactured materials. Quartz is the most common form. Cristobalite and tridymite are other crystalline forms that may be relevant in selected industrial or high-temperature processes.
Concrete, mortar, brick, block, stone, sand, tile, grout, cementitious products, asphalt-containing aggregate, engineered stone, and other materials may contain crystalline silica. The amount varies by material and source.
“Respirable” describes the particle-size fraction capable of penetrating into the gas-exchange region of the lungs. A respirable sampler is designed to collect that size-selective fraction. It does not collect or represent all visible dust in the air.
Cutting, grinding, drilling, crushing, chipping, polishing, demolition, sweeping, abrasive blasting, and other disturbance can create very fine airborne particles. Dust may remain airborne, settle onto surfaces, migrate through openings, or be transported on clothing, tools, equipment, and debris.
Method planning and analytical sensitivity
We review the material, tool, activity, shift, work zone, engineering controls, respirator use, weather, ventilation, containment, and reason for sampling.
A cyclone or other accepted respirable sampler and suitable filter media are selected in coordination with the laboratory and applicable method.
Pumps are calibrated using a representative sampler assembly at the flow rate required for the selected device, method, and particle-size convention.
Personal samples are positioned in the breathing zone. Area samples are located according to the migration, perimeter, background, or project-monitoring objective.
Task duration, tools, materials, water use, local exhaust, vacuum systems, respirators, housekeeping, weather, production rate, and interruptions may be recorded.
Laboratory results are reviewed with sample volume, reporting limit, duration, worker and task representation, controls, blanks, and the applicable comparison criteria.
Choosing the correct sample type
The sampler is worn by the worker near the nose and mouth. It is intended to represent the employee’s inhalation exposure during the monitored work period.
The sampler remains at a fixed location. It can document conditions near a work zone, occupied space, perimeter, containment boundary, or suspected migration pathway.
Dust is collected from a documented surface or area. The result may identify or quantify crystalline silica within the sampled deposited dust.
Dust generation, sampling and migration
Residential and adjacent-space investigations
Dust migration may occur when cutting, grinding, drilling, demolition, or debris handling is performed without adequate isolation, local exhaust, wet methods, negative pressure, housekeeping, or protection of occupied areas.
Common pathways include doors, corridors, stairwells, elevator shafts, plumbing and electrical penetrations, risers, pipe chases, floor openings, ceiling voids, façade openings, shared walls, HVAC returns, fan-coil units, ductwork, and unsealed containment.
An assessment may include complaint and work-history review, photographs, visible-dust observations, containment review, pressure relationships, real-time particle screening, area air sampling, settled-dust sampling, HVAC inspection, and appropriate comparison areas.
OSHA’s occupational exposure limits should not be presented as residential clearance standards. Residential, public-adjacent, or property-damage evaluations require site-specific interpretation based on the sample type, work history, dust distribution, sources, background, cleaning, and purpose of the assessment.
Deposited construction dust
Laboratory analysis can identify or quantify crystalline silica in the specific dust collected from a documented surface. Multiple locations can help evaluate source-to-pathway patterns, affected rooms, adjacent areas, or cleaning effectiveness.
The result may support documentation that silica-containing dust was present in a sampled area, but it should be considered with other dust constituents and field observations.
Settled-dust testing does not directly measure the airborne concentration during the original work, the worker’s breathing-zone exposure, the duration of exposure, or the dose inhaled by an occupant.
A non-detect on one surface does not prove that every room, content, carpet, HVAC component, concealed area, or previously cleaned location is free of silica-containing dust.
There is no generally applicable federal health-based clearance standard for crystalline silica mass in settled dust in a private residence. Results should not be labeled as passing or failing a universal residential silica-dust limit.
Interpretation should address the source, material, work activity, spatial pattern, comparison areas, sample area, laboratory method, cleaning history, and project objective.
Corrective work may involve source control, isolation, HEPA-filtered vacuuming, damp wiping or wet cleaning, appropriate handling of porous materials, HVAC review, and prevention of cross-contamination.
The cleaning protocol should be tailored to the dust quantity, affected materials, property use, contents, access, and other contaminants that may also be present.
Countertop fabrication and installation
Engineered-stone products can contain a high proportion of crystalline silica. Cutting, grinding, polishing, edge finishing, sink cutouts, drilling, dry fabrication, on-site modification, installation, cleanup, and waste handling can generate respirable dust.
Exposure assessment should consider shop and field work, dry versus wet methods, local exhaust, tool shrouds, production rate, worker position, secondary employees, housekeeping, compressed air, contaminated clothing, enclosed vehicles, and residual dust.
Personal breathing-zone sampling is generally needed to evaluate employee exposure. Area air and settled-dust samples may additionally address bystander, adjacent-area, shop, residential, or post-work contamination questions.
Read the current NIOSH countertop-worker guidanceOccupational exposure criteria — reviewed August 17, 2026
OSHA’s permissible exposure limit for respirable crystalline silica is 50 micrograms per cubic meter of air, calculated as an eight-hour time-weighted average.
OSHA’s action level is 25 micrograms per cubic meter as an eight-hour TWA. Exposure-assessment and other obligations depend on the applicable standard and conditions.
Construction employers may follow specified Table 1 controls for covered tasks or use exposure assessment and controls under the alternative exposure-control provisions.
Open the construction standardThe general-industry and maritime standard addresses exposure assessment, regulated areas, controls, respiratory protection, medical surveillance, communication, housekeeping, and records.
Open the general-industry standardA short area sample, perimeter sample, residential sample, surface sample, or particle-counter reading should not be compared directly with an eight-hour employee exposure limit unless the sampling design and calculation legitimately represent the required occupational exposure metric.
Sampling and reporting process
We review the worker, task, material, complaint, work area, controls, property use, project phase, regulatory objective, and documentation needs.
Personal, task, area, perimeter, baseline, particle, or settled-dust samples are selected with suitable durations and laboratory sensitivity.
Pumps are calibrated with representative sampler assemblies and samples are collected during documented work or environmental conditions.
Tools, materials, controls, work duration, ventilation, containment, dust pathways, housekeeping, weather, and interruptions may be recorded.
Samples are submitted to a qualified laboratory using NIOSH Method 7500 or another analytical method suitable for the project.
Results are reviewed with sample representation, volume, task, location, reporting limits, controls, comparison criteria, and stated limitations.
Project documentation
Important limitations
Air and dust samples represent selected workers, tasks, locations, surfaces, durations, materials, controls, and conditions included in the sampling plan. Results can change with production rate, tool use, weather, ventilation, containment, work practices, housekeeping, worker position, material composition, and sample duration.
A low or non-detect result for one sample does not prove that crystalline silica is absent from every worker exposure, task, shift, room, surface, HVAC component, concealed area, work zone, or condition not represented by the sampling plan.
Area air monitoring does not automatically represent employee exposure. Settled-dust testing is not an airborne concentration. Real-time particle monitoring does not identify quartz, cristobalite, or tridymite without laboratory analysis.
OSHA’s action level and permissible exposure limit are occupational criteria. They should not be described as residential, occupant, environmental, property-damage, or settled-dust clearance standards.
A sample with insufficient air volume, a high laboratory reporting limit, filter overloading, mineral interference, pump interruption, unrepresentative task conditions, or inadequate documentation may not support the intended comparison or conclusion.
Environmental and occupational testing does not diagnose silicosis, lung cancer, chronic obstructive pulmonary disease, kidney disease, or any individual medical condition. Medical concerns should be addressed by an appropriate health care professional.
Official silica standards and technical resources
These official resources address health effects, construction and general-industry standards, sampling and analysis, engineering controls, countertop work, mining, and New York City construction-dust requirements.
OSHA information on silica-related disease, construction and general-industry standards, compliance resources, training, and exposure control.
Open OSHA silica resources OSHA Construction Silica ResourcesConstruction-standard guidance concerning Table 1, exposure assessment, written control plans, engineering controls, respirators, and housekeeping.
Open construction resources OSHA General Industry and MaritimeCompliance resources for regulated areas, exposure assessment, controls, medical surveillance, respiratory protection, communication, and records.
Open general-industry resources CDC / NIOSH NIOSH Crystalline Silica MethodsOfficial NIOSH method listing for crystalline silica, including Method 7500 by X-ray diffraction and complementary analytical approaches.
Open NIOSH methods CDC / NIOSH Health Effects of Occupational ExposureNIOSH review of silicosis, lung cancer, obstructive lung disease, renal effects, autoimmune effects, exposure, and prevention.
Open NIOSH health-effects review CDC / NIOSH Countertop Worker ExposureCurrent worker guidance for engineered-stone and countertop fabrication, installation, controls, respirators, housekeeping, and exposure prevention.
Open countertop guidance MSHA Mining Silica Final Rule ResourcesMine Safety and Health Administration resources concerning respirable crystalline silica exposure limits, sampling, controls, and respiratory protection.
Open MSHA resources NYC DEP Construction Dust Control RulesNew York City rules concerning dust-generating operations and controls intended to prevent construction dust from becoming airborne.
Open NYC dust rulesExternal links are provided for public information. Their inclusion does not imply that any government agency endorses, certifies, or is affiliated with Angstrom Testing Services LLC. Requirements must be confirmed for the specific employer, worker, jurisdiction, contract, material, task, exposure scenario, and current law.
Related environmental testing
Regional air and dust sampling
Angstrom provides silica air monitoring, settled-dust testing, employee exposure assessment, construction-dust investigation, and industrial hygiene consulting throughout New York City, Long Island, Westchester, southern Connecticut, eastern New Jersey, and nearby areas.
Serving Nassau County, Suffolk County, Queens, and nearby Long Island communities.
View Rockville Centre location New York City Office Park Avenue, ManhattanServing Manhattan and construction, transit, residential, commercial, institutional, and public projects throughout all five boroughs.
View Manhattan location Westchester Office White Plains, NYServing White Plains and communities throughout lower, central, and northern Westchester.
View White Plains locationDust, renovation and building resources
Technical guidance on breathing-zone monitoring, fixed-location air sampling, settled-dust testing, NIOSH Method 7500 and interpretation limits.
Read silica testing guide Renovation Dust EPA Renovation, Repair and Painting RuleRelated guidance concerning renovation containment, dust control, cleaning and documentation where multiple building hazards may overlap.
Read renovation guide Settled Dust Lead Dust Testing: Dust Wipes, Results & NYC/EPA StandardsA related example of how measured surface areas, sample locations, dust migration and laboratory results are documented and interpreted.
Read lead-dust guideSilica testing FAQs
Respirable crystalline silica consists of quartz, cristobalite, or tridymite contained in airborne particles small enough to penetrate into the gas-exchange region of the lungs. It may be generated when concrete, brick, mortar, stone, tile, engineered stone, or other silica-containing materials are disturbed.
Monitoring may be useful during cutting, coring, grinding, drilling, chipping, demolition, repointing, façade work, countertop fabrication, tunnel work, abrasive blasting, or other tasks that can generate respirable silica-containing dust.
Yes. A respirable sampler can be placed in the worker’s breathing zone to evaluate representative exposure during selected tasks, work periods, or shifts. The plan should document materials, controls, tools, respirators, and worker activities.
NIOSH Method 7500 is an X-ray diffraction method used to analyze crystalline silica collected on a filter. The laboratory may report quartz, cristobalite, and tridymite, subject to the method, sample loading, interferences, and laboratory capability.
No. A particle counter can document particle-number or mass-estimate patterns within selected size channels, but it cannot determine whether the particles contain quartz, cristobalite, or tridymite. Laboratory analysis is required.
Yes. Dust can be collected from selected documented surfaces to evaluate whether crystalline silica is present in deposited dust after construction, demolition, masonry, countertop, façade, or migration events.
No. Settled-dust testing evaluates selected deposited dust. Occupational exposure monitoring uses personal breathing-zone air samples designed to represent the worker’s airborne exposure during the monitored work period.
No. OSHA’s action level and permissible exposure limit are occupational eight-hour time-weighted-average criteria. They are not residential, occupant, settled-dust, property-damage, or universal environmental clearance standards.
No. A non-detect applies to the selected sample and its reporting limit. It does not prove absence from every room, surface, content, carpet, HVAC component, concealed area, previously cleaned location, task, or time period.
Yes. A project may include visual inspection, work-history review, containment assessment, pathway evaluation, area air sampling, particle screening, HVAC review, settled-dust testing, comparison areas, and written findings.
No. Angstrom provides independent testing, exposure assessment, sampling, industrial hygiene consulting, laboratory coordination, and reporting. We do not perform construction, demolition, dust cleanup, remediation, or abatement.
Yes, when included in the agreed scope. Documentation may include project history, workers or locations monitored, sampling methods, calibrations, flow rates, durations, laboratory results, interpretation, limitations, photographs, controls, and recommended next steps.
Angstrom provides silica testing in New York City, Long Island, Westchester, southern Connecticut, eastern New Jersey, and nearby areas. Availability depends on the project type, required equipment, laboratory sensitivity, duration, access, urgency, and reporting needs.
Discuss the work activity or dust concern
Describe the property or workplace, location, material, cutting or demolition activity, workers or areas of concern, dates and duration, dust controls, containment, cleaning, complaint history, and whether you need personal exposure monitoring, area or perimeter air sampling, baseline testing, settled-dust testing, or written project documentation.
Client feedback
Selected Google reviews from clients who used Angstrom for environmental testing, consulting and written project support.
“It was a refreshing experience doing business with Paul and Angstrom Testing Services. They are professional, straightforward and budget friendly. Detailed, precise and on time. I recommend them and would do business with them anytime!”
“Great to work with! We had a very short deadline and needed results in a day - they made it happen. Paul quickly got back to me with any questions I had.”
“Paul is great. He's smart, trustworthy, reliable and communicative. I would recommend Paul to anyone looking for a tester!”
These reviews concern Angstrom's environmental testing and consulting services and are not presented as silica-specific testimonials. This block does not add review structured data.
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