AGT Labs Industrial Hygiene

Crystalline Silica Testing — XRD & RCS Lab, Houston TX

Need silica testing in Houston? AGT Labs analyzes samples collected by your industrial hygienist, EHS team or consultant — drop off at 10200 East Freeway, Suite 101, or ship from anywhere in the U.S. As Houston's premier crystalline silica testing lab, our AIHA IHLAP-accredited industrial hygiene testing laboratory at 10200 East Freeway, Houston TX 77029 provides XRD (NIOSH 7500 / OSHA ID-142 v4) analysis with polymorph speciation for quartz and cristobalite (the polymorphs on our AIHA IHLAP scope). AIHA IHLAP LAP-101470 and ISO/IEC 17025:2017 accredited — continuous AIHA accreditation since 2000. Personal exposure monitoring, respirable dust gravimetric analysis, and bulk material quantification — OSHA 1910.1053 and 1926.1153 compliant results accepted nationwide.

AIHA IHLAP · LAP-101470 ISO/IEC 17025:2017 (AIHA-LAP) NIOSH 7500 · OSHA ID-142 v4 Rush 1-Day TAT In-House XRD Since 2000
Are you a silica exposure or industrial hygiene inspector or consultant? We're the accredited lab behind your sample results. Independent Lab Testing →
Why Silica Testing Matters

Silica exposure is invisible — only air monitoring confirms your controls work

OSHA Enforcement

OSHA 1910.1053 and 1926.1153 carry penalties up to $16,550 per violation per day. Construction employers who skip Table 1 compliance or fail to monitor face stop-work orders and criminal referrals.

Silicosis Prevention

Silicosis is incurable and progressive. RCS particles that reach the alveoli trigger permanent fibrosis. OSHA's PEL of 50 µg/m³ was set precisely because lower concentrations still cause disease over a working lifetime.

Legal & Liability Shield

Workers' comp and tort claims for occupational silicosis are increasingly successful. Documented, accredited IH testing history from an ISO/IEC 17025 lab is your primary legal defense against exposure claims.

Baseline Assessments

Employers are required to assess the exposure of each employee who is or may reasonably be expected to be exposed to RCS at or above the action level (25 µg/m³).

Industrial Hygiene Testing Lab

What Is Crystalline Silica (RCS) Testing?

Crystalline silica is a mineral found in sand, stone, concrete, mortar, and many industrial materials. When workers cut, grind, drill, blast, or crush these materials, they generate airborne particles small enough to penetrate deep into the lung — called Respirable Crystalline Silica (RCS).

Common Exposure Triggers Across Industries

Silica exposure doesn't only happen on construction sites. Any process that cuts, grinds, drills, or crushes materials containing crystalline silica generates respirable dust. In manufacturing, foundry operations and glass production are high-risk. Oil and gas operations using silica sand for hydraulic fracturing expose workers during sand handling and blending. Countertop fabrication — particularly with engineered stone containing 90%+ quartz — has emerged as one of the highest-risk occupations for silicosis, with multiple clusters of accelerated silicosis reported among young workers. Even agriculture and landscaping operations that disturb sandy ground can produce exposures above the OSHA action level.

How Often Should You Monitor?

OSHA requires initial exposure assessments for each job classification or task where silica exposure is reasonably expected. If initial results exceed the action level (25 µg/m³), periodic monitoring must continue at least every six months. If two consecutive measurements taken at least seven days apart show exposures below the action level, monitoring may stop until conditions change. Any change in production processes, controls, or personnel requires reassessment. AGT Labs recommends annual verification sampling even when results are consistently below the AL, as equipment wear, new materials, and seasonal conditions can shift exposure levels unexpectedly.

Silica testing measures the exact airborne concentration of RCS in the breathing zone of workers using personal sampling pumps, cyclones, and pre-weighed PVC filters. Our crystalline silica testing laboratory analyzes these filters via X-Ray Diffraction (XRD) and reports results in µg/m³ for direct comparison to the OSHA PEL (50 µg/m³) and Action Level (25 µg/m³). As an AIHA IHLAP-accredited IH testing lab (LAP-101470) operating under ISO/IEC 17025:2017, AGT Labs provides crystalline silica analysis using XRD (NIOSH 7500 / OSHA ID-142 Version 4) — our AIHA-accredited primary method.

  • Airborne RCS monitoring via XRD (NIOSH 7500 / OSHA ID-142 Version 4) — AIHA IHLAP-accredited
  • Total and respirable dust gravimetric analysis (NIOSH 0500/0600)
  • Bulk material characterization for silica content
  • Quantification of specific polymorphs — Quartz and Cristobalite (accredited scope)
  • Defensible data for OSHA "Table 1" compliance alternatives
  • Federal & DoD project support — AIHA IHLAP + ISO/IEC 17025 quality system
Construction worker wearing personal air sampling pump and cyclone for silica testing
Analysis Methods

Our Silica & Dust Testing Methods

As a specialized crystalline silica testing lab, we know that choosing the correct analytical method is critical for regulatory compliance. Workers exposed to crystalline silica are often co-exposed to nuisance particulate. For gravimetric analysis of non-silica fractions, see our total and respirable dust testing services.

X-ray diffraction instrument analyzing crystalline silica air sample filter at AGT Labs AIHA-accredited laboratory
METHOD 03

Respirable & Total Dust

Gravimetric analysis to determine the total mass of dust collected. We highly recommend pairing Respirable Dust (NIOSH 0600) with your Silica XRD analysis to get a complete picture of the worker's exposure profile from a single filter.

Standard:NIOSH 0500 (Total) / 0600 (Resp.)
Media:Pre-weighed PVC filter
Report:mg/m³ dust concentration
Bonus:Can be run before XRD on the same filter
METHOD 04

Bulk Silica Quantification

Determines the exact percentage of crystalline silica in raw bulk materials — concrete, grout, sand, stone, aggregate, or industrial minerals. Required when an employer needs to characterize the silica content of materials before beginning work, or for SDS compliance documentation.

Standard:XRD / NIOSH 7500 (Modified)
Media:Bulk material (powder, chunk, slurry)
Report:% crystalline silica by weight per polymorph

Quick Method Selector — Which silica test do you need?

OSHA compliance monitoring for workers (accredited result)?
→ XRD (NIOSH 7500 / OSHA ID-142 v4) — AIHA-accredited
Need full worker exposure profile?
→ NIOSH 0600 (dust) + NIOSH 7500 (XRD)
Foundry, high-temp, or unknown minerals?
→ XRD (NIOSH 7500) — required where cristobalite may be present
Characterize raw material before work begins?
→ Bulk XRD — % silica by weight
Validate wet suppression or LEV system?
→ Pre/post-control XRD personal monitoring
Method Sensitivity

Detection Limits & Sample Volume Planning

What sample volume do you need to certify a result below the OSHA Action Level (25 µg/m³)? Here's the headroom each method provides at typical full-shift sample volumes.

Sampling ScenarioCycloneVolumeXRD LOD (µg/m³)vs OSHA AL (25 µg/m³)vs OSHA PEL (50 µg/m³)
4-hr Partial ShiftDorr-Oliver Nylon @ 1.7 L/min408 L~12 µg/m³~2× below AL~4× below PEL
8-hr Full ShiftDorr-Oliver Nylon @ 1.7 L/min816 L~6 µg/m³~4× below AL~8× below PEL
8-hr Full ShiftSKC Aluminum @ 2.5 L/min1,200 L~4 µg/m³~6× below AL~12× below PEL
8-hr Full ShiftBGI GS-3 @ 2.75 L/min1,320 L~4 µg/m³~6× below AL~12× below PEL
Bulk Material XRDn/a — bulk sample≥ 1 g sample~0.1% by weightn/an/a

Why volume matters more than method

For documented compliance below the OSHA Action Level, target at least 800 L of sample volume — this gets you to a ~6 µg/m³ XRD reporting limit, providing 4× headroom below the 25 µg/m³ AL. Partial-shift sampling (under 4 hours) often produces volumes too low to certify a non-detect against the AL, leaving the result inconclusive.

If you must use partial-shift sampling for short-duration tasks, switch to a higher-flow cyclone (SKC Aluminum at 2.5 L/min or BGI GS-3 at 2.75 L/min) to compensate. Critical: never substitute one cyclone's flow rate for another — this invalidates the particle size cut-point and renders the sample unusable. For accredited compliance reporting, use XRD only.

Crystalline Silica Minerals

Three Regulated Silica Polymorphs We Identify

Not all silica is the same. Polymorph identity matters for regulatory treatment, health risk assessment, and which analytical method reliably detects each form. XRD (NIOSH 7500) identifies quartz and cristobalite separately.

Quartz
α-Quartz · Most Common Form
OSHA Regulated~95% of Exposures
The most abundant form of crystalline silica in the earth's crust. Found in sand, concrete, mortar, granite, sandstone, slate, and most silica-bearing construction materials. The primary cause of occupational silicosis. The OSHA PEL of 50 µg/m³ applies to quartz as well as the other polymorphs. NIOSH REL: 50 µg/m³ TWA.
Cristobalite
High-temperature silica polymorph
OSHA RegulatedHigh-Temp Processes
Forms when quartz is heated above 1,470°C — found in foundry sand, refractory ceramics, volcanic rock, and some calcined diatomaceous earth products. Considered more biologically reactive than quartz — its NIOSH IDLH is 25 mg/m³ versus 50 mg/m³ for quartz (the REL itself is the same 50 µg/m³ for all polymorphs). XRD is required to quantify cristobalite. Disproportionately hazardous in foundry and kiln environments.
AIHA IHLAPLAP-101470
ISO/IEC 17025:2017 (AIHA-LAP)Accredited Testing Lab
XRD MethodsNIOSH 7500 · OSHA ID-142 v4
IH Lab LocationHouston TX 77029
Continuous AIHASince 2000
OSHA Construction Standard

OSHA Table 1 — Construction Tasks & Required Controls

OSHA 29 CFR 1926.1153 Table 1 lists 18 construction tasks with prescribed engineering controls. Full implementation = exemption from baseline air monitoring. Partial implementation, deviation, or unlisted tasks require objective air monitoring data — that's where AGT Labs' XRD analysis comes in.

Construction workers cutting concrete block generating visible silica dust cloud requiring OSHA respirable crystalline silica monitoring
Construction TaskRequired Engineering ControlRespirator if < 4 hrs/dayRespirator if ≥ 4 hrs/day
Stationary masonry sawsIntegrated water delivery systemNone requiredNone required
Handheld power sawsIntegrated water delivery systemNone outdoors / APF 10 indoorsAPF 10 (filtering facepiece N95 or half-mask)
Walk-behind sawsIntegrated water deliveryNone outdoorsNone outdoors / APF 10 indoors
Drivable saws (outdoor)Integrated water deliveryNoneNone
Rig-mounted core saws/drillsWater-fed toolingNoneNone
Handheld & stand-mounted drillsShroud + dust collector (≥ 25 CFM/inch)NoneNone
Dowel drilling rigs (concrete)Shroud + dust collector + HEPA-filtered vacuumAPF 10APF 10
Vehicle-mounted drilling rigsDust collector + control boothNoneNone
Jackhammers & handheld powered chipping toolsWater OR dust collector (HEPA-filtered)None outdoors / APF 10 indoorsAPF 10 (half-mask required)
Handheld grinders for mortar removal (tuckpointing)Shroud + HEPA-filtered dust collectorAPF 10APF 25 (full-face PAPR)
Handheld grinders (other than mortar removal)Water OR shroud + HEPA dust collectorNone outdoorsNone outdoors / APF 10 indoors
Walk-behind milling machines & floor grindersWater OR HEPA dust collectionNoneNone
Small drivable milling machinesWater-fed cutting drumNoneNone
Crushing machinesWater spray + ventilated boothAPF 10APF 10
Heavy equipment in earthmovingEnclosed, climate-controlled cabNoneNone
Heavy equipment for demolition / abrasive blastingEnclosed cab + water suppressionAPF 10APF 25 (full-face PAPR)
Abrasive blasting (silica sand)Banned in EU/UK; restricted in USSubstitute with non-silica abrasive OR conduct exposure assessment

When you need air monitoring instead of Table 1

Three common scenarios force you out of Table 1 and into mandatory air monitoring: (1) the task isn't on Table 1 (e.g., scarifying, demolition of pre-1981 silica-bearing materials, mineral processing); (2) the engineering control specified can't be implemented (no water available, dust collector below required CFM, etc.); or (3) general industry work covered by 29 CFR 1910.1053 — Table 1 does NOT apply to general industry. In any of these cases, full-shift personal XRD monitoring documents your compliance status and protects you in the event of an OSHA inspection.

Regulatory Standards

OSHA Silica Standards — Construction vs General Industry

OSHA regulates respirable crystalline silica under two separate standards, each tailored to the industries they cover. Understanding which standard applies to your operation determines your monitoring obligations, engineering control requirements, and medical surveillance responsibilities.

29 CFR 1926.1153 — Construction

Effective June 23, 2017, this standard applies to all construction activities where workers may be exposed to respirable crystalline silica. Key provisions include:

  • Table 1 Alternative: Employers can follow prescribed engineering controls for 18 specified tasks instead of conducting exposure monitoring
  • PEL: 50 µg/m³ as an 8-hour TWA
  • Action Level: 25 µg/m³ — triggers initial monitoring and medical surveillance
  • Medical Surveillance: Required within 30 days of initial assignment for workers exposed above the AL for 30+ days/year
  • Competent Person: Must be designated to implement the written exposure control plan

29 CFR 1910.1053 — General Industry & Maritime

Effective June 23, 2018, this standard covers manufacturing, foundries, hydraulic fracturing, and all non-construction operations. There is no Table 1 equivalent — employers must conduct exposure assessments. Key provisions include:

  • PEL: 50 µg/m³ as an 8-hour TWA (same as construction)
  • Action Level: 25 µg/m³ — same threshold, same consequences
  • Exposure Assessment: Required for all workers who may be exposed — no table-based exemption
  • Engineering Controls: Required as the primary means of reducing exposure before respirators
  • Housekeeping: Prohibits dry sweeping and compressed air for silica dust cleanup

Both standards share the same PEL and action level, but their implementation paths differ. Construction employers can use Table 1 controls for listed tasks; general industry employers must always start with an exposure assessment. AGT Labs' AIHA IHLAP-accredited XRD analysis meets the documentation requirements of both standards — our reports include TWA calculations, PEL comparisons, and the chain-of-custody records regulators expect.

Report Deliverables

Every Method, Every Standard, Every Deliverable

No surprises in your silica testing report. Here's exactly what each analysis from our industrial hygiene testing lab returns — methods, media, and deliverables side by side.

Analysis TypeMethod / StandardSample MediaReport DeliverableRush?
Crystalline Silica — XRD (Accredited)NIOSH 7500 / OSHA ID-142 v437mm PVC filter (5.0 µm) + cycloneµg/sample quartz + cristobalite · TWA · PEL comparison · AIHA IHLAP-accreditedYes
Respirable Dust GravimetricNIOSH 0600Pre-weighed PVC filter + cyclonemg/m³ total respirable dust · OSHA PEL comparisonYes
Total Dust Gravimetric (PNOR)NIOSH 0500Pre-weighed PVC filter (no cyclone)mg/m³ particulate not otherwise regulatedYes
Dual: Dust + XRD SilicaNIOSH 0600 + NIOSH 7500Single pre-weighed PVC filter + cyclonemg/m³ respirable dust + µg/m³ silica per polymorph · both PEL comparisonsYes
Bulk Silica ContentXRD / NIOSH 7500 (Mod)Bulk material (powder, chunk)% crystalline silica by weight · polymorph breakdownCall
Lab Logistics

Turnaround Times & Free Sampling Media

Every rush option and kit detail — clearly laid out before you submit your first sample.

Silica Monitoring Isn't One-and-Done

OSHA 1910.1053 and 1926.1153 require periodic re-monitoring above the 25 µg/m³ Action Level, and any change in task, material, or engineering controls triggers a fresh round. Set up a recurring program or standing account and we'll hold your pre-weighed filters and loaner pumps, set your recurring submission calendar, and apply volume pricing across silica and paired dust testing.

Set Up a Monitoring Program
Turnaround OptionTimelineSurcharge
Standard Analysis5+ Business DaysNo Surcharge
4-Day Rush4 Business Days+25%
3-Day Rush3 Business Days+50%
2-Day Rush2 Business Days+75%
1-Day Rush1 Business Day+100%
Samples received before 2:00 PM CT logged same day. Call (713) 453-6090 to confirm rush capacity for large silica batches. Dual dust+silica (NIOSH 0600 + 7500) available at combined pricing.

Sampling Media & Equipment

  • Pre-weighed 37mm PVC filters (5.0 µm pore size)
  • Matched weight filter pairs for gravimetric QA
  • Dorr-Oliver nylon cyclones (1.7 L/min)
  • SKC aluminum cyclones (2.5 L/min)
  • Calibrated personal air sampling pumps — loaner program
  • Field blank filters (10% of batch, pre-labeled)
  • Pre-paid UPS return shipping label
  • Industrial Hygiene Chain of Custody form
Download IH COC Form
Field Protocol Reference

Silica Sampling Field Requirements

Silica testing is unforgiving of poor field protocol. Using the wrong flow rate for your specific cyclone will invalidate the particle size cut-point, rendering the data useless for OSHA compliance. Full reference: IH Sampling & Analysis Guide.

Industrial hygienist calibrating respirable dust cyclone and personal air sampling pump for crystalline silica exposure monitoring
Cyclone Flow Rates
Dorr-Oliver (Nylon)
1.7 L/min exactly. Most common cyclone in US field work. Flow must be maintained within ±5% throughout the shift. Calibrate before and after sampling with the cyclone in-line.
SKC Aluminum
2.5 L/min exactly. Higher flow rate — do not substitute Dorr-Oliver flow rate for this cyclone. Document the cyclone make/model on the COC or results cannot be validated.
BGI GS-3
2.75 L/min. Less common but fully NIOSH-validated. Record exact cyclone model and serial number on COC.
Calibration
Calibrate before and after each sampling day with the complete sampling train (cyclone + cassette + filter) in-line using a primary standard. Record both readings on COC.
Filter & Volume Requirements
Filter media
37mm PVC filter, 5.0 µm pore size ONLY. MCE filters used for asbestos and metals are incompatible — they cannot be analyzed by XRD for silica.
Sample volume
Minimum 400–1,000 liters to reach the method LOD relative to the Action Level (25 µg/m³). Full-shift sampling (816 L at 1.7 L/min) is strongly recommended for OSHA compliance documentation.
Filter overloading
If visible dust is heavy, cap volume at 200 L to prevent filter overloading which prevents accurate gravimetric weighing and XRD analysis. Note loading concern on COC.
Field blanks
Submit at least two field blanks per sampling event, or 10% of the total sample count (whichever is greater). Open cassette at sampling location for 30 seconds, seal immediately. Label as "field blank" on COC.
Dual Dust + Silica Protocol
Pre-weighing
For combined dust + silica analysis, filters must be pre-weighed by the lab before shipping to you. Do not use field-purchased filters — they may not be gravimetrically tared to sufficient precision.
Cassette handling
After sampling, keep the cassette upright. Avoid dropping or shaking — dislodged dust that falls to cassette walls will NOT be captured in the gravimetric weighing, artificially lowering the result.
Transportation
Ship in the cassette shipping container provided. Do not remove filters from cassettes in the field. The lab performs all filter handling under controlled conditions.
COC fields
Record: cyclone model, pre-/post-calibration flow rates, start/stop times, calculated total volume (L), worker name, task performed, and any engineering controls in use.
Shipping & Drop-Off
IH Lab address
10200 East Freeway, Suite 101, Houston TX 77029. Before 2:00 PM CT for same-day log-in. Call (713) 453-6090.
Carrier
UPS Ground preferred. Pre-paid return label included in kit. For large batches, call ahead — rush XRD slots are capacity-limited per day.
Temperature
No special temperature requirements for PVC silica filters. Do not ship near strong solvents or acids — filter degradation will affect gravimetric accuracy.
COC completion
All COC fields must be completed before submission. Incomplete volume information prevents TWA calculation — the report cannot be used for OSHA compliance without a valid volume.
Submission Workflow

From Sample Collection to Final Report

1

Request Kit & Pumps

Contact us to request pre-weighed PVC filters, cyclones, and loaner pumps. We ship nationwide.

2

Collect Air Samples

Deploy pumps on workers using exact flow rates required by your specific cyclone type.

3

Ship to IH Lab

Keep cassettes upright. Complete COC with flow rates and total volumes. Ship to our Houston IH testing lab.

4

Gravimetric & XRD

We weigh the filters for total respirable dust, then perform XRD analysis for specific silica polymorphs.

5

Compliance Report

Receive your detailed report comparing detected concentrations against OSHA PELs via our secure portal.

Standards & Regulatory Context

OSHA Silica Regulations Explained

The 2016 OSHA Silica Rule drastically lowered permissible exposure limits. Here is how our IH testing services help you comply. Foundry and metalworking operations that generate silica dust from grinding or sandblasting may also require a full metals in air ICP scan and mercury vapor testing to evaluate concurrent metal fume and vapor exposure.

OSHA 29 CFR 1926.1153 — Construction
Requires employers to limit exposure to the PEL of 50 µg/m³. Employers must either strictly follow the engineering controls in "Table 1" or conduct objective air monitoring to prove exposures are below the PEL.
OSHA 29 CFR 1910.1053 — General Industry
Applies to manufacturing, maritime, and hydraulic fracturing. Unlike construction, there is no "Table 1" safe harbor. General industry employers MUST conduct baseline exposure assessments via air testing.
NIOSH REL — Recommended Exposure Limit
NIOSH recommends a REL of 50 µg/m³ for respirable crystalline silica, applying equally to quartz and cristobalite. Cristobalite's higher biological potency is instead reflected in its IDLH of 25 mg/m³, versus 50 mg/m³ for quartz. Our XRD analysis separately quantifies each polymorph.
MSHA — Mining Applications
The Mine Safety and Health Administration enforces silica exposure limits in mining. MSHA uses NIOSH 7500 (XRD) for compliance monitoring. AGT Labs' ISO/IEC 17025 accredited XRD results are accepted for MSHA compliance.
AIHA IHLAP — IH Lab Accreditation (LAP-101470)
Our AIHA IHLAP accreditation (ID: LAP-101470) under the Industrial Hygiene Laboratory Accreditation Program certifies that every silica analysis — sample preparation, XRD diffraction, quantification, and reporting — is performed under validated, AIHA-LAP, LLC accredited (ISO/IEC 17025:2017) traceable procedures.
Medical Surveillance Trigger
Under both 1910.1053 and 1926.1153, workers exposed to RCS at or above the Action Level (25 µg/m³) for 30 or more days per year must be enrolled in a medical surveillance program including chest X-rays and spirometry.
Federal & DoD Procurement Support
AGT Labs' AIHA IHLAP accreditation (LAP-101470) and ISO/IEC 17025:2017 quality system support federal procurement, BRAC remediation programs, and federal facility cleanup contracts that require accredited industrial hygiene testing. Silica testing data from an AIHA IHLAP-accredited lab meets federal data quality requirements for Tier I and Tier II investigations.
EPA NESHAP & State Air Programs
Bulk silica content data is required for SDS labeling under HazCom 2012, EPA NESHAP source determination, and many state air permitting programs (TCEQ in Texas). Our bulk XRD analysis quantifies % crystalline silica per polymorph for these regulatory uses.
Industries & Clients

Who Relies on Our Crystalline Silica Testing Lab

Many construction and demolition sites pair silica monitoring with asbestos testing, PCB testing, and PAH testing to satisfy OSHA, EPA NESHAP, and TSCA requirements under a single chain of custody.

Construction & Concrete Work

GCs, subcontractors, and concrete cutting specialists — silica monitoring for OSHA 1926.1153 Table 1 alternatives, saw cutting, coring, grinding, and jackhammering operations. Renovation projects involving composite wood products may also require formaldehyde testing to address concurrent indoor air hazards.

Oil & Gas / Hydraulic Fracturing

Frac sand handling, blending, and pumping operations across oilfield and upstream oil & gas sites generate some of the highest silica exposures measured in any industry. OSHA 1910.1053 baseline and periodic monitoring for well-site supervisors, blender operators, and sand transfer crews.

Foundries & Metal Casting

Foundry operations using silica sand molds generate cristobalite. XRD (NIOSH 7500) with quartz and cristobalite reporting is essential for OSHA 1910.1053 compliance in iron, steel, and aluminum foundry and metal fabrication environments.

Abrasive Blasting Operations

Sand blasting, shot blasting, and surface prep contractors — Texas OSHA-regulated environments where exposures can exceed the PEL by 10–50× without proper controls. Surface coating operations following blasting may also require isocyanate exposure monitoring for polyurethane and epoxy applications.

Industrial Hygiene Consultants

Environmental and IH consulting firms across Texas, Gulf Coast, and nationwide — bulk sample and IH testing analysis with accredited XRD results, complete with TWA calculations and OSHA PEL comparisons formatted for client reports and citations defense.

Ceramics, Glass & Mining

Ceramics and glass manufacturing (cristobalite risk), stone quarrying, and surface mining — MSHA and OSHA 1910.1053 compliance monitoring. Bulk silica content characterization for raw materials and SDS documentation.

Federal & DoD Facilities

BRAC remediation, federal building demolition, military airfield concrete work, navy shipyard abrasive blasting, and DoD environmental cleanup require accredited silica analytical data. Our AIHA IHLAP accreditation (LAP-101470) and ISO/IEC 17025:2017 quality system support federal facility silica testing under TSCA, CERCLA, and DoD environmental data quality requirements.

Client Support

Silica Testing — Frequently Asked Questions

What is the OSHA PEL for respirable crystalline silica?
The OSHA Permissible Exposure Limit (PEL) for respirable crystalline silica is 50 µg/m³ as an 8-hour time-weighted average (TWA). The OSHA Action Level (AL) is 25 µg/m³ — exceeding the AL triggers mandatory periodic exposure monitoring, employee notification, medical surveillance for workers exposed 30+ days per year, and a written exposure control plan.
What methods does your crystalline silica testing lab use?
AGT Labs primarily uses X-Ray Diffraction (XRD) following NIOSH 7500 and OSHA ID-142 Version 4 methodologies — these are AGT Labs' AIHA IHLAP-accredited methods for crystalline silica analysis and the gold standard for distinguishing quartz and cristobalite. XRD is required for foundry, kiln, and high-temperature environments where cristobalite may be present.
Do you provide cyclones and sampling pumps?
Yes. With 5 business days' notice, we provide pre-weighed PVC filters (typically 37mm, 5.0 µm), sampling cassettes, and aluminum or nylon cyclones. We also offer a pump loaner program equipped with calibrated personal air sampling pumps for qualifying clients. Cyclones must match required flow rates: Dorr-Oliver Nylon at 1.7 L/min, SKC Aluminum at 2.5 L/min, BGI GS-3 at 2.75 L/min.
What is the required air volume for silica sampling?
Required volume depends on the cyclone used to achieve the necessary limit of detection. Typically, a minimum of 400 to 1,000 liters is recommended. A full-shift sample (8 hours at 1.7 L/min = 816 L) provides excellent headroom below the OSHA Action Level (25 µg/m³). Flow rates vary strictly by cyclone model — using the wrong flow rate invalidates the particle-size cut-point and renders the sample unusable for OSHA compliance.
When is silica air testing legally required?
Under OSHA 1926.1153 (Construction) and 1910.1053 (General Industry), employers must assess employee exposure to silica if it may be at or above the Action Level of 25 µg/m³. For construction, if you are not fully implementing the engineering controls specified in 'Table 1', objective air monitoring data is legally required. General industry employers cannot use Table 1 — baseline air monitoring is mandatory.
Can you analyze both respirable dust and silica from the same filter?
Yes. We can perform a gravimetric analysis for total respirable dust (NIOSH 0600) and then subsequently analyze that exact same PVC filter for crystalline silica via XRD (NIOSH 7500). This provides a complete exposure profile from a single worker sample at significantly lower combined cost than running separate analyses on separate filters.
What turnaround times do you offer for silica testing?
Standard results are delivered in 5+ business days with no surcharge. Rush options are available: 4-day (+25%), 3-day (+50%), 2-day (+75%), and 1-day (+100%). Samples received before 2 PM CT are logged on the same day. XRD rush slots are capacity-limited — call (713) 453-6090 for large rush batches to confirm instrument availability.
Is AGT Labs accredited for crystalline silica testing?
Yes. AGT Labs holds AIHA IHLAP accreditation under certificate LAP-101470 and operates under ISO/IEC 17025:2017 quality standards — continuously accredited since February 2000 (25+ years). Our IHLAP scope covers XRD crystalline silica analysis (NIOSH 7500 and OSHA ID-142 Version 4) for quartz and cristobalite.; for accredited compliance reporting, XRD is the method of record. All silica testing is performed in-house at our Houston TX laboratory.
What is OSHA Table 1 and how does it relate to silica monitoring?
OSHA Table 1 (29 CFR 1926.1153(c)) is a list of 18 specified construction tasks (saw cutting, grinding, drilling, etc.) with prescribed engineering controls (water suppression, LEV, vacuum dust collection) and respirator requirements. If a construction employer fully implements all Table 1 controls for the matched task — including specific water flow rates, vacuum CFM minimums, and respirator selection — they are exempt from baseline exposure monitoring. If any Table 1 control is not fully implemented, or the task is not on Table 1, objective air monitoring data is required to demonstrate compliance with the 50 µg/m³ PEL. Table 1 does NOT apply to general industry under 1910.1053.
What is the difference between the OSHA Action Level and PEL for silica?
The OSHA Permissible Exposure Limit (PEL) for respirable crystalline silica is 50 µg/m³ as an 8-hour TWA — the legal compliance limit. The OSHA Action Level (AL) is 25 µg/m³ — half the PEL — and triggers mandatory periodic monitoring, written exposure control plan, employee notification of results, and medical surveillance for workers exposed 30+ days per year. Exposures below the AL allow employers to discontinue periodic monitoring after two consecutive measurements. Exposures above the AL but below the PEL trigger the AL program elements but are not citations. Exposures above the PEL are violations subject to OSHA penalties.
How long are silica samples stable in shipping?
PVC filters with collected silica dust are exceptionally stable — silica is a mineral and does not degrade. Samples can be shipped at ambient temperature without refrigeration and remain stable for 30+ days. AGT Labs recommends shipping within 7 days of collection to maintain chain of custody. Critical handling rule: keep cassettes upright after sampling. Dust dislodged onto cassette walls will not be captured in the gravimetric weighing, artificially lowering reported concentrations. Ship in the original cassette shipping container — do not remove filters from cassettes in the field.
Does AGT Labs perform silica testing for federal projects and DoD facilities?
Yes. AGT Labs' AIHA IHLAP accreditation (LAP-101470) and ISO/IEC 17025:2017 quality system support federal procurement, BRAC site remediation, military installation environmental work, and Department of Defense contracts that require accredited industrial hygiene testing. Our IHLAP scope for NIOSH 7500 and OSHA ID-142 v4 supports silica testing for federal building demolition, military airfield concrete work, navy shipyard abrasive blasting operations, and DoD environmental cleanup activities. All XRD analysis is performed in-house at the Houston laboratory.
Houston TX IH Laboratory

Crystalline Silica Lab Serving Houston's Industrial Base

AGT Labs is located at 10200 East Freeway, Suite 101, Houston TX 77029 — within the Houston Ship Channel industrial corridor. All XRD silica analysis is performed in-house. No send-outs. Samples received before 2:00 PM CT logged same day.

Construction
Concrete Cutting & Coring
XRD silica monitoring for Houston-area concrete cutting, coring, and grinding contractors — OSHA 1926.1153 Table 1 alternative compliance for high-rise construction, infrastructure projects, and commercial renovation.
Energy
Frac Sand Operations
OSHA 1910.1053 monitoring for Texas Permian Basin and Eagle Ford frac sand handling — wellsite blender operators, sand transfer crews, and supervisor exposure documentation.
Heavy Industry
Foundry & Casting
XRD with quartz and cristobalite reporting for Houston-area iron, steel, and aluminum foundries — cristobalite detection is essential.
Federal
DoD & BRAC Projects
AIHA IHLAP-accredited XRD for military airfield concrete work, navy shipyard abrasive blasting, federal facility decommissioning, and BRAC environmental cleanup activities.
25+
Years AIHA
Accredited
3
Polymorphs
Quantified by XRD
1-Day
Rush XRD
TAT Available
77029
Houston TX
10200 E. Freeway

Ready to Work with an Accredited Crystalline Silica IH Testing Lab?

AIHA IHLAP (LAP-101470) · ISO/IEC 17025:2017 · XRD (NIOSH 7500 / OSHA ID-142 v4) AIHA-accredited · Pump Loaner Program · Rush 1-Day TAT · Houston TX 77029. Ask about recurring monitoring programs and volume pricing for periodic OSHA silica compliance and multi-shift sampling.