Total & Respirable Dust Testing Laboratory

Gravimetric dust analysis via NIOSH 0500 (total) and NIOSH 0600 (respirable) from an ISO/IEC 17025 accredited Houston lab. Personal exposure monitoring, substance-specific PEL compliance, and combined dust + silica co-analysis — OSHA and NIOSH standards accepted nationwide.

ISO/IEC 17025 Accredited AIHA LAP · ID: LAP-101470 Rush Turnaround Available Dust + Silica Co-Analysis
Why Dust Testing Matters

Airborne dust is invisible at dangerous concentrations — monitoring is the only proof controls work

OSHA PNOR Enforcement

OSHA's PNOR limits — 15 mg/m³ total, 5 mg/m³ respirable — apply when no substance-specific PEL exists. Dozens of specific substances (wood dust, grain, coal, cotton) carry their own lower PELs. Citations follow failure to monitor and control.

Chronic Lung Disease

Long-term inhalation of fine respirable particles causes irreversible conditions — occupational asthma, COPD, hypersensitivity pneumonitis, and chronic bronchitis. Gravimetric monitoring is the baseline tool for quantifying risk and justifying engineering controls.

Legal & Insurance Defense

Documented air monitoring history from an ISO/IEC 17025 accredited laboratory is the primary legal defense against occupational lung disease claims. No monitoring history = no defense. OSHA requires records retained for at least 30 years.

Control Verification

LEV systems, water suppression, enclosures, and process changes reduce dust generation — but only air sampling confirms the reduction meets regulatory limits. Pre- and post-control monitoring is required documentation for engineering change records.

Gravimetric Dust Analysis

What Is Total & Respirable Dust Testing?

Professional dust testing is the process of collecting airborne particulate matter from a worker's breathing zone or a work area using a calibrated sampling pump and filter media, then precisely weighing the collected dust in our laboratory using analytical microbalances accurate to 0.001 mg.

The result — reported in milligrams per cubic meter of air (mg/m³) — is compared to applicable OSHA Permissible Exposure Limits (PELs) or NIOSH Recommended Exposure Limits (RELs). For respirable dust in silica-generating environments, the same filter can proceed directly to XRD analysis (NIOSH 7500) for crystalline silica quantification without re-sampling.

  • Total airborne particulate monitoring — NIOSH 0500 (all particle sizes)
  • Respirable fraction monitoring — NIOSH 0600 with cyclone size selector
  • Combined dust + crystalline silica from one filter (NIOSH 0600 + 7500)
  • Wood dust, grain dust, coal dust, and cotton dust testing and monitoring
  • Area, task-specific, and engineering control validation sampling
  • Personal breathing-zone exposure assessments for OSHA PEL compliance
Industrial hygiene technician conducting personal air sampling for total and respirable dust testing OSHA compliance
Understanding Dust Fractions

Total Dust vs. Respirable Dust — Key Differences

Choosing the wrong fraction for your dust testing scenario can result in invalid data. Here's exactly when OSHA and NIOSH require each fraction, what media they use, and what limits apply.

Total Dust
NIOSH 0500 — All airborne particles
Particle sizeAll sizes captured (inhalable fraction)
Sampler37mm open-face cassette — no cyclone
Flow rate2.0 L/min
Filter media37mm PVC or MCE (depending on co-analysis)
OSHA PEL (PNOR)15 mg/m³ (8-hr TWA)
Use whenWood dust, grain, cotton, coal, nuisance dust monitoring
Laboratory Methods

Four Dust Analysis Methods

Every dust testing method at AGT Labs uses precision microbalances traceable to NIST standards. Filter pairs are conditioned in a desiccator before and after sampling to eliminate humidity effects on mass readings.

METHOD 01

Total Airborne Particulate

Gravimetric analysis of all airborne particles collected by open-face cassette. Appropriate for nuisance dust, wood dust, grain dust, and any substance where OSHA specifies a total dust PEL. Reports total mass collected and mg/m³ concentration.

Standard:NIOSH 0500
Media:37mm PVC filter, open-face cassette
Flow rate:2.0 L/min
Report:mg collected + mg/m³ + OSHA PEL comparison
METHOD 02

Respirable Dust Gravimetric

Cyclone-separated respirable fraction weighing. Used in all environments where fine particle penetration to the pulmonary region is the primary concern — silica, coal, hard metals, mineral dusts. Can proceed directly to silica XRD analysis.

Standard:NIOSH 0600
Media:Pre-weighed 37mm PVC filter + cyclone
Flow rate:1.7 L/min (Dorr-Oliver) / 2.5 L/min (SKC)
Report:mg collected + mg/m³ + OSHA PEL comparison
Bonus:Filter reused for silica XRD
METHOD 03

Combined Dust + Silica (XRD)

Our most requested analysis for construction, mining, and foundry environments. A single PVC filter is gravimetrically weighed for total respirable dust (NIOSH 0600), then subjected to XRD analysis (NIOSH 7500) for quartz, cristobalite, and tridymite. Two compliance datasets from one sample, one pump, one shift.

Standards:NIOSH 0600 + NIOSH 7500
Media:Pre-weighed 37mm PVC filter + cyclone
Report:mg/m³ dust + µg/m³ silica by polymorph · both PEL comparisons
METHOD 04

Substance-Specific Dust Testing

When the dust contains a substance with its own OSHA PEL (wood, grain, coal, cotton, flour), we report against that specific limit. Includes coal mine dust analysis per OSHA ID-125G, wood dust analysis for OSHA 1910.1000 Table Z-1, and grain dust per 29 CFR 1910.272.

Standards:NIOSH 0500 / 0600 · OSHA ID-125G
Media:PVC filter — open-face or cyclone per substance
Report:mg/m³ vs. substance-specific PEL + NIOSH REL
Lab AccreditationISO/IEC 17025:2017
IH Lab AccreditationAIHA LAP · ID: LAP-101470
Environmental TestingPJLA Accredited
Lab LocationHouston TX · In-House Analysis
Regulatory PEL Reference

Dust-Specific OSHA PELs & NIOSH RELs

When a substance-specific PEL exists, it replaces the PNOR general limit — and is almost always lower. AGT Labs reports against the applicable specific standard in your sample report.

Dust TypeFractionOSHA PELNIOSH RELStandard
PNOR (Nuisance Dust)Total15 mg/m³10 mg/m³OSHA Z-1
PNOR (Nuisance Dust)Respirable5 mg/m³3 mg/m³OSHA Z-1
Wood Dust (all species)Total5 mg/m³1 mg/m³OSHA Z-1 / NIOSH
Wood Dust (western red cedar)Total5 mg/m³0.5 mg/m³NIOSH REL (sensitizer)
Grain Dust (wheat, corn, barley)Total10 mg/m³4 mg/m³29 CFR 1910.272
Cotton Dust (raw)Total (lint-free)1 mg/m³0.2 mg/m³29 CFR 1910.1043
Coal Mine DustRespirable2.0 mg/m³1.0 mg/m³OSHA ID-125G / MSHA
Flour DustTotal15 mg/m³ (PNOR)0.5 mg/m³NIOSH REL
Crystalline Silica (Quartz)Respirable50 µg/m³50 µg/m³OSHA 1910.1053

* Silica results in µg/m³, all other dust limits in mg/m³. OSHA PELs as 8-hour TWA. Contact AGT Labs for substance-specific limit guidance before sampling. Ask our scientists →

Lab Logistics

Turnaround Times & Free Sampling Media

Turnaround Options
1-Day Rush1 business day+100%
2-Day Rush2 business days+75%
3-Day Rush3 business days+50%
4-Day Rush4 business days+25%
Standard7+ business daysNo Surcharge
Samples received before 2:00 PM CST logged same day. For combined dust + silica orders, the silica turnaround schedule applies. Call (713) 453-6090 to confirm rush capacity.

Sampling Media & Equipment

  • Pre-weighed 37mm PVC filters (5.0 µm pore) — gravimetric & XRD compatible
  • Matched tare-weight filter pairs for precision gravimetry
  • Open-face cassettes for total dust (NIOSH 0500)
  • Closed-face cassettes + cyclones for respirable dust (NIOSH 0600)
  • 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 (pre-labeled)
  • Industrial Hygiene Chain of Custody form + pre-paid return shipping
Download IH COC Form

Kits ship via UPS Ground with 5 business days notice. Houston metro courier pickup available: (713) 453-6090.

Field Protocol Reference

Dust Sampling Field Requirements

Gravimetric accuracy depends entirely on correct field technique. Filter moisture, pump flow drift, and cassette handling errors can invalidate results even when the laboratory work is perfect.

Total Dust (NIOSH 0500)
Cassette setup
Open-face 37mm cassette. Remove the top plug only — leave the side plugs in. Orient face-down in the worker's breathing zone. No cyclone needed or permitted.
Flow rate
2.0 L/min. Calibrate before and after each sampling day with the open-face cassette in-line. Record both readings on the COC.
Sample volume
Minimum 200–480 L for a full shift. Low-dust environments may require the full 8-hour shift to collect enough mass for accurate weighing above the method LOD (0.05 mg).
Field blanks
Minimum 2 per batch, or 10% of total (whichever is greater). Open the cassette at the sample location for 30 seconds, then reseal. Submit with samples.
Respirable Dust (NIOSH 0600)
Cyclone setup
Attach cyclone to closed-face cassette per manufacturer instructions. Cyclone must be oriented vertically upright during sampling — tilting shifts the cut-point and invalidates the respirable fraction.
Flow rate
Dorr-Oliver nylon: 1.7 L/min. SKC aluminum: 2.5 L/min. Wrong flow rate = wrong particle size cut = non-compliant data. Document cyclone make/model on COC — lab cannot validate without it.
Pre-weighed filters
Filters must be pre-weighed by the laboratory before shipment. Do not use un-weighed field-purchased filters — the gravimetric result requires a tare weight precise to 0.001 mg.
After sampling
Keep cassette upright. Do not drop, shake, or invert. Dislodged particles that fall from the filter to the cassette wall are not captured in the gravimetric weighing, artificially lowering the measured mass.
Pump Calibration & Documentation
Calibration
Calibrate before and after sampling with the complete sampling train (pump + tubing + cassette + cyclone if used) in-line. Record start flow, end flow, start time, end time, and calculated volume on COC.
Flow drift
If pre/post flows differ by more than ±10%, average the two flows for volume calculation and flag the sample. Differences >20% should be noted in the report narrative — OSHA may challenge the data.
COC fields
Record: method requested, worker name/job task, start/stop time, pre-calibration flow, post-calibration flow, total calculated volume (L), cyclone model (if used), any controls in operation.
Multiple pumps
When sampling multiple workers simultaneously, assign and document each pump serial number to each cassette on the COC. Results are worker-specific — mix-ups invalidate individual exposure comparisons.
Shipping to AGT Labs
Lab address
10200 East Freeway, Suite 101, Houston TX 77029. Received before 2:00 PM CST = same-day log-in.
Carrier
UPS Ground preferred with pre-paid return label included in kit. Keep cassettes upright in the shipping container provided. No dry ice or refrigeration needed for gravimetric-only samples.
Rush samples
Call (713) 453-6090 to alert the lab before shipping rush samples. This ensures a balance and analyst are prioritized for your batch on arrival.
Combined dust + silica
Note "NIOSH 0600 + NIOSH 7500" on the COC. Filters will be gravimetrically weighed first, then transferred to XRD analysis. No additional filter handling required from the client.
Submission Workflow

From Sample Collection to Certified Dust Report

1

Request Media & Pumps

Contact AGT Labs for pre-weighed PVC filters, cassettes, cyclones, and loaner pumps. Allow 5 business days. Houston pickup available.

2

Deploy & Sample

Place pump in breathing zone. Match flow rate to sampler. Record pre/post calibration flows and total volume on IH COC form.

3

Ship to Houston Lab

Keep cassettes upright. Ship via UPS with pre-paid label. Received before 2:00 PM CST = same-day log-in and weigh-in.

4

Gravimetric Analysis

Filters desiccated and precision-weighed on NIST-traceable microbalances. Combined orders proceed to XRD silica analysis on the same filter.

5

Compliance Report

Results on secure portal — mg/m³ concentration, TWA, OSHA PEL comparison, LOD, analyst signature, accreditation number.

Industries & Clients

Who Relies on AGT Labs for Dust Testing

Construction & Demolition

Concrete cutting, drywall sanding, demolition, and masonry work — respirable dust testing (NIOSH 0600) paired with silica XRD for comprehensive OSHA 1926.1153 Table 1 alternative documentation on Gulf Coast job sites.

Woodworking & Lumber

Sawmills, cabinet shops, flooring manufacturers, and millwork operations — total dust monitoring (NIOSH 0500) against the OSHA wood dust PEL of 5 mg/m³ and NIOSH REL of 1 mg/m³ for all wood species.

Grain Handling & Food Processing

Grain elevators, flour mills, food ingredient processors — total dust monitoring (NIOSH 0500) against OSHA grain dust PEL (10 mg/m³) and NIOSH REL (4 mg/m³). Grain dust is also explosible — monitoring supports dual safety and hygiene programs.

Mining & Aggregate

Surface and underground mining — coal mine dust (OSHA ID-125G / MSHA), respirable mineral dust, and combined silica co-analysis. AGT Labs XRD results are accepted for MSHA compliance documentation.

IH Consultants & EH&S

Industrial hygiene consulting firms, environmental health & safety departments, and third-party monitoring contractors — accredited gravimetric results formatted for client reports, OSHA response packages, and engineering control ROI documentation.

Chemical & Pharmaceutical

Active pharmaceutical ingredient (API) powder handling, chemical manufacturing, and pigment production — substance-specific dust monitoring with reporting against OSHA PELs, NIOSH RELs, and OELs for proprietary compounds on request.

Client Questions

Total & Respirable Dust Testing — Frequently Asked Questions

What is the difference between total dust and respirable dust?
Total dust (NIOSH 0500) captures all airborne particles using an open-face cassette — no size selection. Respirable dust (NIOSH 0600) uses a cyclone to isolate particles smaller than 10 µm that penetrate deep into lung tissue. Respirable dust is more toxicologically significant because these particles deposit in the alveolar region where clearance is slow and damage accumulates over time.
What are the OSHA PELs for total and respirable dust?
For Particulates Not Otherwise Regulated (PNOR): total dust PEL is 15 mg/m³ and respirable dust PEL is 5 mg/m³ (both 8-hour TWA). However, when a substance-specific PEL exists — wood dust, grain dust, cotton dust, coal dust — that limit applies and is almost always lower than the PNOR limit. NIOSH recommends even more conservative RELs for most substances.
Do I need a cyclone for dust testing and sampling?
A cyclone is required only for respirable dust sampling (NIOSH 0600). The cyclone separates particles by aerodynamic diameter, allowing only the fine respirable fraction to reach the filter. Total dust sampling (NIOSH 0500) uses a standard open-face 37mm cassette at 2.0 L/min with no size selector. Using a cyclone for a total dust sample, or omitting one for a respirable dust sample, renders the result non-compliant.
Can you analyze dust and silica from the same filter?
Yes — this is one of the most cost-effective approaches for silica-generating environments. We perform NIOSH 0600 gravimetric analysis first (total respirable dust in mg/m³), then analyze the same pre-weighed PVC filter for crystalline silica via XRD (NIOSH 7500). You receive both datasets — mg/m³ dust concentration and µg/m³ silica per polymorph — from a single worker sample and a single pump deployment.
What is the OSHA PEL for wood dust?
OSHA's PEL for wood dust is 5 mg/m³ total dust (8-hour TWA) under 29 CFR 1910.1000 Table Z-1. NIOSH recommends a far more conservative REL of 1 mg/m³ for all wood species — and only 0.5 mg/m³ for western red cedar due to its sensitizing properties. AGT Labs reports against both OSHA PEL and NIOSH REL in the wood dust sample report.
What is the OSHA PEL for grain dust?
OSHA's PEL for grain dust (wheat, corn, barley) is 10 mg/m³ total dust (8-hour TWA) under 29 CFR 1910.272. NIOSH recommends 4 mg/m³. Note that grain dust is also explosible at concentrations above 20–60 g/m³ — gravimetric monitoring serves both an industrial hygiene compliance function and provides data relevant to explosion hazard assessment programs.
What turnaround times do you offer for dust testing and gravimetric analysis?
Standard: 7+ business days at no surcharge. Rush: 4-day (+25%), 3-day (+50%), 2-day (+75%), 1-day (+100%). Samples received before 2:00 PM CST are logged same day. For combined dust + silica (NIOSH 0600 + 7500), the silica turnaround schedule applies. Call (713) 453-6090 to confirm rush capacity for large batches.
What media do I need for combined dust + silica sampling?
Combined dust + silica analysis requires a pre-weighed 37mm PVC filter (5.0 µm pore size) in a closed-face cassette with a cyclone. The filter must be pre-weighed by AGT Labs — field-purchased un-tared filters cannot be used for gravimetric analysis. Note "NIOSH 0600 + NIOSH 7500" on the COC. MCE or glass fiber filters cannot be used — they are incompatible with XRD silica analysis.
Do you provide sampling pumps and equipment?
Yes. With 5 business days notice, we provide complete sampling media kits: pre-weighed PVC filters, cyclones, open-face and closed-face cassettes, field blank filters, COC forms, and pre-paid return shipping. We also offer a pump loaner program with calibrated personal air sampling pumps for qualifying clients. Contact us at (713) 453-6090 or info@agtlabs.com.

Ready to Submit Samples for Dust Testing or Request Media?

ISO/IEC 17025 accredited · AIHA LAP · NIOSH 0500 · NIOSH 0600 · Dust + Silica Co-Analysis · Rush TAT · Houston TX

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