VOC Testing, BTEX & TO-15 Laboratory
Comprehensive airborne VOC testing and volatile organic compound analysis for occupational compliance and environmental screening. Personal BTEX exposure monitoring by NIOSH 1501 — ambient and indoor VOC testing by EPA TO-15 — GC-MS analysis in-house at our Houston TX laboratory.
Benzene has no safe exposure level — OSHA's action level is 0.5 ppm, and petrochemical operations routinely exceed it without active monitoring
Benzene Is an IARC Group 1 Carcinogen
Benzene is a confirmed human carcinogen — the highest IARC classification — and is directly linked to acute myeloid leukemia (AML) and other blood cancers. OSHA's Benzene Standard (29 CFR 1910.1028) requires documented monitoring any time exposures may exceed the 0.5 ppm action level. There is no recognized safe threshold.
OSHA Enforcement Is Active in Petrochemical
Benzene and BTEX violations are among the most frequently cited in refinery, chemical plant, and petroleum handling inspections across Texas. Without documented personal exposure monitoring records, any OSHA inspection following a health incident creates immediate citation risk. Monitoring records are your legal shield.
Unknown VOC Mixtures Are Invisible Hazards
Solvent degreasing, surface coating, adhesive application, chemical reactions, and building material off-gassing all generate airborne VOC mixtures whose composition workers cannot see, smell reliably, or assess without VOC testing and laboratory analysis. EPA TO-15 identifies every VOC present — including ones you didn't expect.
Vapor Intrusion Is a Growing Liability
Petroleum hydrocarbons (benzene, MTBE) and chlorinated solvents (TCE, PCE) from subsurface contamination migrate into overlying buildings — creating occupant exposure without any visible soil or groundwater issue. EPA TO-15 sub-slab and indoor air sampling is the defensible regulatory standard for vapor intrusion characterization.
VOC Testing Methods: BTEX, TVOC & TO-15 — Which Do You Need?
AGT Labs offers all three analytical platforms. The right test depends on whether you need personal occupational compliance, a rapid field screen, or broad compound identification. Many projects require more than one.
BTEX Testing
Benzene · Toluene · Ethylbenzene · Xylenes — targeted aromatic hydrocarbon monitoring for petroleum and chemical workers
BTEX testing is the required occupational monitoring approach when workers are exposed to petroleum-derived aromatic solvents — refinery operations, fuel handling, chemical manufacturing, tank cleaning, painting, and solvent degreasing. The four BTEX compounds are quantified individually with results compared directly to OSHA PELs, ACGIH TLVs, and NIOSH RELs. Benzene — the most hazardous of the four — has an OSHA action level of just 0.5 ppm, making sensitive analytical methods essential.
TVOC Testing
Total Volatile Organic Compounds — aggregate screening for IAQ baseline, building offgassing, and process monitoring
TVOC testing is a non-speciated total concentration measurement — all VOCs summed into one value, typically in ppb or µg/m³. Photo-ionization detector (PID) field instruments provide real-time TVOC readings for leak detection and rapid pre-screening. Laboratory TVOC testing is the sum of all compounds detected by GC-MS from a TO-15 sample. TVOC results help determine whether a facility requires more detailed compound-specific analysis and support LEED certification, post-renovation offgassing assessment, and odor complaint investigations.
EPA TO-15 VOC Testing
60+ VOC whole-air canister analysis — the regulatory standard for ambient air, vapor intrusion, and unknown VOC screening
EPA Method TO-15 VOC testing uses SUMMA-polished stainless-steel evacuated canisters to collect a true "whole air" sample without chemical adsorption bias. The canister is returned to the laboratory for GC-MS analysis, simultaneously identifying and quantifying 60+ targeted VOCs down to sub-ppbv concentrations. TO-15A (2019 update) expands the target list and refines QC requirements. This is the preferred and frequently required method for vapor intrusion investigations, EPA permit compliance, Clean Air Act HAPs monitoring, and any situation where the VOC mixture is unknown or complex.
BTEX & Benzene Testing
Targeted personal exposure monitoring for Benzene, Toluene, Ethylbenzene, and Xylenes via NIOSH 1501 (charcoal tubes) to ensure OSHA PEL compliance in petrochemical and refining operations.
OSHA PEL, Action Level, ACGIH TLV & NIOSH REL — All Compared
Benzene is the reason BTEX monitoring programs exist. Its regulatory limits are among the most stringent for any common workplace chemical — and they differ significantly between OSHA, ACGIH, and NIOSH. AGT Labs reports against all three.
Why Benzene Dominates BTEX Compliance Programs
Benzene is present in virtually every petroleum product, from crude oil and gasoline to refinery process streams and aromatic solvents. Unlike toluene and xylenes — which are irritants and CNS depressants — benzene is a bone marrow toxin and confirmed human carcinogen that causes acute myeloid leukemia (AML) and aplastic anemia at long-term exposures below 1 ppm. The NIOSH REL of 0.1 ppm reflects this carcinogenicity — it is 10 times more protective than OSHA's PEL. AGT Labs uses NIOSH 1501 GC-FID analysis for routine benzene compliance monitoring, with detection limits well below the OSHA action level, ensuring all exceedances are captured and reported with full confidence.
Laboratory Methods for BTEX & Benzene Fenceline
NIOSH 1501 — BTEX by GC-FID
The occupational monitoring standard for personal 8-hour TWA BTEX compliance — the method OSHA expects for benzene PEL documentation. Uses activated charcoal tubes with a personal sampling pump, adsorbing aromatic hydrocarbons during a full work shift, then desorbing with CS₂ for GC-FID analysis.
EPA 325A/325B — Fenceline Monitoring
EPA's Refinery Sector Rule (40 CFR Part 63 Subpart CC) requires continuous fenceline benzene monitoring using passive sorbent tubes deployed for two-week integrated sampling periods along facility perimeters. AGT Labs supports these programs with passive tube supply, analysis, and result reporting.
NIOSH 1501 BTEX — Charcoal Tube Protocol
EPA TO-15 VOC Testing
Simultaneously detect 60+ volatile organic compounds using GC-MS and SUMMA Canisters. The regulatory standard for vapor intrusion, ambient air monitoring, and unknown VOC identification.
What is EPA TO-15 VOC Testing?
EPA TO-15 VOC testing uses evacuated SUMMA stainless-steel canisters to capture a true "whole air" grab or time-integrated sample, which is then analyzed by GC-MS. Because the sample is collected directly into a vacuum without relying on chemical adsorption media (like charcoal), it detects a massive spectrum of VOCs down to sub-ppbv concentrations simultaneously.
TO-15 vs TO-15A: EPA Method TO-15A (published 2019) is an updated revision that expands the target compound list from 64 to 70+ compounds and clarifies QC requirements. For most routine VOC screening, TO-15 and TO-15A produce equivalent results. TO-15A is increasingly required by state air permit compliance testing. AGT Labs performs both — specify your required version on the COC.
- Detects 60+ VOCs simultaneously (BTEX, Chlorinated, HAPs)
- Vapor intrusion investigations (sub-slab and indoor air)
- Unknown odor or health complaint identification
- EPA permit compliance and fenceline monitoring
- Sub-ppbv detection limits for regulatory review
60+ VOCs Detected Simultaneously from One SUMMA Canister
The following groups represent the standard EPA TO-15 target analyte list. All compounds are identified and quantified simultaneously in a single GC-MS analysis — no separate runs required for different compound classes.
- Benzene BTEX · OSHA
- Toluene BTEX
- Ethylbenzene BTEX
- o/m/p-Xylene BTEX
- MTBE Fuel Oxygenate
- n-Hexane Fuel · OSHA
- n-Heptane Fuel
- Cyclohexane Fuel
- Isooctane Fuel
- Styrene EPA HAP
- Naphthalene EPA HAP
- Cumene EPA HAP
- Trichloroethylene (TCE) Chlorinated
- Perchloroethylene (PCE) Chlorinated
- 1,1,1-Trichloroethane Chlorinated
- Methylene chloride OSHA
- Chloroform Chlorinated
- Carbon tetrachloride Chlorinated
- Vinyl chloride IARC 1 · HAP
- 1,2-Dichloroethane Chlorinated
- cis-1,2-Dichloroethylene Chlorinated
- 1,2-Dichloropropane Chlorinated
- Chlorobenzene Chlorinated
- 1,4-Dichlorobenzene Chlorinated
- Acetone Solvent
- Methyl ethyl ketone (MEK) Solvent
- Methyl isobutyl ketone Solvent
- 4-Methyl-2-pentanone Solvent
- Ethyl acetate Solvent
- Butyl acetate Solvent
- Isopropyl alcohol (IPA) Solvent
- Acrylonitrile EPA HAP · IARC 2B
- Acrolein EPA HAP
- Carbon disulfide Neurotoxin
- Tetrahydrofuran (THF) Solvent
- 1,4-Dioxane TO-15A
* Full TO-15 target list includes 64 compounds per original method; TO-15A expands to 70+. Contact AGT Labs to confirm current scope or add custom analytes.
EPA TO-15 — SUMMA Canister Protocol
TVOC Screening & IAQ Baselines
Aggregate Total Volatile Organic Compound (TVOC) analysis for initial indoor air quality assessments, building offgassing evaluation, and LEED certification.
What is TVOC Testing?
TVOC (Total Volatile Organic Compounds) is a non-speciated aggregate measurement of all VOCs present in the air, typically calculated as the sum of all detected individual VOCs from a GC-MS (TO-15) analysis, or measured via a PID field instrument.
TVOC results help determine whether a facility requires more detailed compound-specific analysis and support LEED certification, post-renovation offgassing assessment, and odor complaint investigations.
Note: TVOC alone does NOT provide compound-specific data required for OSHA compliance. Specific methods (NIOSH 1501, TO-15) are required for regulatory occupational documentation.
- Initial IAQ baseline screening in offices, schools, and hospitals
- Post-construction and renovation material offgassing
- Pre-screening before deciding on compound-specific GC-MS analysis
- LEED v4/v4.1 EQc Indoor Air Quality Assessment
Six Common Scenarios — Which VOC Testing Method to Order
The right VOC testing method depends on your regulatory driver, the exposure setting, and whether compound identification or compliance quantification is the goal.
Refinery / Petrochemical Benzene Compliance
Workers in petroleum refining, chemical production, and fuel transfer operations are commonly exposed to benzene above the OSHA action level of 0.5 ppm. OSHA's Benzene Standard requires documented personal monitoring, medical surveillance, and records retention.
Indoor Air Quality (IAQ) & Building Assessment
Office buildings, schools, healthcare facilities, and residential properties require VOC testing for LEED certification, post-construction offgassing evaluation, tenant complaints, or pre-occupancy clearance after renovation or remediation activities.
Vapor Intrusion Investigation
Sub-slab and indoor air samples collected to characterize vapor intrusion from chlorinated solvent or petroleum hydrocarbon plumes migrating from contaminated soil or groundwater into overlying structures. Sub-slab and indoor air are compared to EPA screening levels.
Unknown Odor & VOC Testing Investigations
When workers or building occupants report unusual odors, eye/throat irritation, or headaches with an unidentified source, a grab sample TO-15 canister captures the air composition at the moment of complaint for full compound identification by GC-MS.
Solvent Degreasing & Surface Coating Operations
Industrial cleaning and coating operations generate methylene chloride, MEK, toluene, xylenes, and other solvents that require personal exposure monitoring. Requires compound-specific analysis against OSHA PELs for each solvent present.
EPA Fenceline Monitoring — Refineries
EPA's Refinery Sector Rule (40 CFR 63 Subpart CC amendments) requires fenceline benzene monitoring using passive sorbent tubes deployed at facility perimeters for two-week integrated sampling periods. Triggers corrective action at ≥9 µg/m³ annual average.
Turnaround Times & Sampling Media Supply
VOC Testing & BTEX Sampling Kits
- Certified SUMMA canisters (1L and 6L) — evacuated, leak-tested, certified clean for TO-15/TO-15A
- Calibrated flow controllers (24-hr integrated or grab sampling)
- Activated charcoal tubes (100/50 mg) for NIOSH 1501 BTEX
- Tenax TA / Carbopack thermal desorption tubes for TO-17
- Passive OVM diffusion badges (3M 3500 series) for screening
- Calibrated low-flow pumps (50–200 mL/min) — loaner program
- Industrial Hygiene Chain of Custody (COC) with pre-coded analytes
- Pre-paid UPS return shipping in protective canister case
Who Relies on AGT Labs for VOC Testing & BTEX Analysis
Petroleum Refining & Petrochemical Manufacturing
The Houston Ship Channel complex houses one of the world's largest concentrations of petroleum and chemical facilities. Routine BTEX monitoring (NIOSH 1501) for OSHA 1910.1028 compliance, turnaround and unit shutdown work, and maintenance operations in benzene-rich process environments.
Environmental Remediation & Phase II ESA
Vapor intrusion investigation sampling using EPA TO-15 (sub-slab and indoor air) for chlorinated solvent and petroleum hydrocarbon plumes. Phase II Environmental Site Assessment VOC screening. Regulatory submittal-ready results with full QC documentation required for state environmental agency review.
Commercial Real Estate & LEED Certification
Pre-occupancy VOC testing for LEED v4/v4.1 EQc Indoor Air Quality Assessment credit. Post-construction offgassing assessment for new buildings. Tenant complaint investigation in commercial office, retail, and healthcare facilities. TO-15 canister analysis for full compound profile.
Oil & Gas Operations
Upstream oil and gas — tank battery and produced water handling facility VOC surveys, vapor-tight integrity checks, and worker personal monitoring at well pads and compression stations. Both grab (TO-15) and personal (NIOSH 1501) sampling for field and occupational compliance programs.
Industrial Coating, Printing & Cleaning Operations
Solvent-based coatings, printing inks, and industrial cleaning operations generate toluene, xylene, MEK, acetone, and methylene chloride vapors requiring personal exposure monitoring. NIOSH 1501 for BTEX components, TO-17 sorbent tube for ketones and other solvents — often ordered together.
IH Consultants & EH&S Compliance Programs
Industrial hygiene consulting firms managing multi-site VOC testing programs across refineries, chemical plants, and mixed industrial facilities. AGT Labs provides AIHA LAP accredited, OSHA-defensible NIOSH 1501 and TO-15 data with tri-limit reporting (OSHA/ACGIH/NIOSH).
VOC Testing & BTEX Analysis — Frequently Asked Questions
What is the OSHA PEL for benzene in air?
What is the difference between EPA TO-15 and NIOSH 1501?
What VOCs does EPA TO-15 detect?
When do I need BTEX testing vs. general VOC testing?
What is TVOC testing and when is it used?
What is vapor intrusion and why does it require TO-15?
Does AGT Labs provide SUMMA canisters and sampling pumps?
What is the difference between TO-15 and TO-15A?
Can you test for benzene in oil and gas facilities for EPA fenceline monitoring?
Ready to Start VOC Testing or BTEX Air Monitoring?
ISO/IEC 17025 · AIHA LAP · EPA TO-15 · NIOSH 1501 · GC-MS In-House · OSHA Benzene Compliance · Houston TX
