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Chemical Safety Evaluation & Testing

Calorimetry and Dust Explosibility Testing

Reaction calorimetry with RC1 and ARC alongside 20 litre sphere, MIKE, and Hartmann tube testing that generates ATEX and NFPA 660 design data

What this study delivers

Calorimetry and Dust
Explosibility Testing

Specialised laboratory testing for reactive chemistry and combustible dust generates the engineering data that underpins vent sizing per DIERS and NFPA 68, suppression design per NFPA 69, ignition source control per IEC 80079 36 and EN 1127 1, and ATEX Zone classification per IEC 60079 10 2. The reaction calorimetry stack of DSC for milligram scale screening, RC1 for millilitre isothermal kinetics, ARC for millilitre scale adiabatic worst case, VSP2 and Phi Tec for 10 millilitre adiabatic two phase work, and Mettler Toledo HEL produces complementary datasets that feed Stoessel criticality and DIERS vent sizing methodology. The dust testing stack of the Hartmann tube for legacy MIE screening, MIKE 3 for modern MIE per EN 13821, the Godbert Greenwald and BAM ovens for MIT per EN 50281 2 1, the 20 litre sphere for Kst and Pmax per EN 14034 and ASTM E1226, and the MEC apparatus per EN 14034 3 generates the parameters required for Zone 20, 21, and 22 classification, vent area calculation, suppression bottle sizing, and inerting LOC determination. Most industrial powder facilities operate without site specific dust data and rely on generic K values that under protect their actual material, and both OSHA NEP and FM Global increasingly demand site specific testing, which is exactly what our team provides.

Calorimetry and Dust Explosibility Testing Overview
Study execution

How the study is executed

A structured, facilitated process that runs from scope definition through close out and produces defensible, actionable outputs.

Dust Sample Preparation & Characterisation

Prepare dust sample per ASTM E1226 / ISO 6184, sieve to typical 200 mesh (<75 μm), measure particle size distribution (laser diffraction), moisture content, and bulk density, align with NFPA 660 sample protocol.

Explosibility Screen (Yes / No)

Conduct explosibility screen per ASTM E1226 modified Hartmann tube or 20 L sphere, classify as explosible (yes / no) per NFPA 660 / IEC 80079 20 2, if yes, proceed to quantitative testing.

Kst / Pmax Testing (20 L Sphere)

Conduct Kst and Pmax testing in 20 L Siwek sphere per ASTM E1226, calculate Kst (bar·m/s) and Pmax (bar), classify per ATEX Dust Class, St 0 (Kst=0), St 1 (0 to 200), St 2 (200 to 300), St 3 (>300).

MIE / MIT / LOC Testing

Conduct MIE (Minimum Ignition Energy) per ASTM E2019, MIT (Minimum Ignition Temperature) per ASTM E1491 (layer) / E2154 (cloud), and LOC (Limiting Oxygen Concentration) per ASTM E2079, align with NFPA 660 / IEC 80079.

Hybrid Mixture & Conductivity Testing

For hybrid dust gas atmospheres, characterise interaction effects, MIE depression, MEC reduction, Kst modification, conduct conductivity testing (volume resistivity per ASTM D257) for static ignition risk assessment.

DHA Input & Vent Sizing Data

Compile testing report with full Kst / Pmax / MIE / MIT / LOC / MEC results, align with NFPA 660 DHA (Dust Hazard Analysis) input requirements, specify vent sizing per NFPA 68 with Kst input, align with NFPA 69 suppression design.

Calorimetry and Dust Explosibility Testing Scope
Study scope

What the study covers in full

DSC screening for milligram scale thermal events covering onset temperature, enthalpy, and decomposition energy
RC1 isothermal calorimetry with kinetic resolution, dose control feedback, and heat flux profile
ARC adiabatic worst case with Phi correction for runaway Time to Maximum Rate and SADT determination
VSP2 and Phi Tec two phase calorimetry for DIERS vent sizing across vapour, gassy, and hybrid systems
20 litre sphere Kst and Pmax testing per EN 14034 1 and 2 with St 1, 2, and 3 classification
Minimum Explosible Concentration testing per EN 14034 3 and ASTM E1515
MIE testing per EN 13821 using MIKE 3 with capacitor discharge across the 1 millijoule to 1000 millijoule range
Minimum Ignition Temperature per EN 50281 2 1 using the Godbert Greenwald cloud and BAM oven layer methods
Limiting Oxygen Concentration determination for inerting strategy
Volume resistivity and chargeability per EN 13335 for electrostatic hazard assessment
Why it matters

Outcomes of Calorimetry and Dust Explosibility Testing

Dust and Energetic Material Hazard Quantification
  • We generate site specific data that replaces generic K values which under protect your actual dust
  • We identify dusts with an MIE below 10 millijoules that require electrostatic bonding control
  • We define defensible vent area, suppression mass, and isolation design
  • We anchor the inerting LOC for your nitrogen blanketing strategy
NFPA 660 UN TDG Testing Defence
  • We meet the NFPA 660 2024 unified DHA data requirement
  • We provide DIERS compliant calorimetric data for two phase vent sizing
  • We support ATEX Zone classification per IEC 60079 10 2 with EN 14034 evidence
  • We provide data that withstands FM Global and OSHA Combustible Dust NEP audits
Process and Storage Design Improvement
  • We target your dust collection ventilation design to the actual MEC and Kst we measure
  • We drive grounding and bonding programmes against measured volume resistivity
  • We set inerting nitrogen flow against the measured LOC
  • We support realistic vent panel and isolation valve specification
Testing Led versus Incident Led Cost
  • We help you avoid the 30 to 50 percent vent and suppression over specification that conservative generic values cause
  • We reduce your inerting nitrogen consumption through measured LOC operation
  • We target electrostatic control investment to genuine MIE risks
  • We support your FM Global premium tier dialogue with measured data
Standards & references

Codes & standards we work to

ASTM E1226, E1515, and E2019 (US dust)EN 14034 1, 2, 3, and 4 (EU dust)EN 13821 (MIE)EN 50281 2 1 (MIT)ASTM E537, E1981, and E2079 (calorimetry)ISO 11357 (DSC)DIERS Project ManualNFPA 660 (unified dust)NFPA 68 and 69 (vent and suppression)IEC 60079 10 2 (Dust Zones)UN TDG Manual of Tests and CriteriaGHS Rev. 10 (UN)MSIHC Schedule 1 (India)
When to engage

Triggers that signal the need

NFPA 660 DHA gap on an existing or new powder processDIERS vent sizing on reactive chemistryInsurer or FM Global request for site specific dataATEX or IECEx Zone classification supporting data needPost incident dust or runaway investigationProcess scale up that requires chemistry specific calorimetric dataUN MTC SADT determination for transport classificationBattery materials, pharma, or metal powder additive manufacturing facility
Industries served

Where Calorimetry and Dust Explosibility Testing applies

Oil & Gas, Upstream

Wellheads, separators, gas compression, FPSO topsides, produced water systems.

UpstreamOffshoreFPSO
Refineries & Petrochemicals

Distillation columns, reactors, heat exchangers, storage spheres, LPG handling.

RefiningPetrochemical
LNG & Gas Processing

Cryogenic exchangers, liquefaction trains, BOG compressors, storage and sendout.

LNGCryogenic
Specialty Chemicals

Reactive systems, batch reactors, solvent handling, runaway reaction scenarios.

ReactiveBatch
Power Generation

Boilers, HRSGs, steam headers, hydrogen systems, ammonia SCR units.

PowerHydrogen
Pharma & Food

Sterile vessels, CIP/SIP, pressure fermenters, solvent recovery, spray dryers.

PharmaFood & Bev
What we deliver

Tangible deliverables

  • DSC, ARC, RC1, and VSP2 and Phi Tec calorimetric test pack
  • 20 litre sphere Kst, Pmax, and St class data per EN 14034
  • MEC test data per EN 14034 3 and ASTM E1515
  • MIE test data per EN 13821 using MIKE 3
  • MIT cloud and layer data per EN 50281 2 1
  • LOC determination for inerting
  • Electrostatic property data covering resistivity and chargeability
  • DHA ready test data package
  • DIERS vent sizing input pack
  • ATEX Zone classification supporting data
Get Started

Ready to start your project?

Speak with our team to scope an engagement tailored to your facility, regulatory context, and lifecycle stage.