Technical depth for real process-safety decisions
Process safety decisions rarely come from a single test result, code requirement, or checklist. HazBasis white papers are designed for engineers, EHS professionals, facility owners, laboratory teams, project managers, and operations personnel who need to understand why a hazard occurs, what data are needed, how those data should be interpreted, and how the results affect process design and safeguards.
Need help applying a white paper to your process? Reach out and we’ll help.
Explore White Papers by Technical Topic
Combustible Dust & Dust Hazard Analysis
Topics Covered:
- Dust explosibility
- Ignition sensitivity
- Explosion severity
- DHA methodology
- NFPA 660 requirements
- Kst/Pmax, MIE, MEC, MAIT/LIT, LOC
- Explosion venting, isolation, suppression, containment
- Electrostatic ignition
PHA, HAZOP, LOPA & QRA
Topics Covered:
- Process Hazard Analysis methodology
- HAZOP node selection and guidewords
- Scenario development
- Safeguard evaluation
- LOPA independent protection layers
- Consequence modeling
- QRA
- Facility siting
- Facilitation pitfalls
PVC Dust Explosion Testing and the Overdriving Effect
PVC dust explosion testing can produce low or weakly positive Kst results that require careful engineering interpretation. This section examines the potential overdriving effect associated with energetic igniters in 20-liter dust explosion testing and explains why a low Kst value alone does not establish that a PVC dust is non-explosible. It also addresses differences among suspension resin, dispersion resin, collected fines, and formulated PVC blends, and provides a framework for determining when additional testing or larger-vessel investigation may be appropriate for a Dust Hazard Analysis (DHA).
Topics Covered:
- PVC dust explosibility and deflagration behavior
- Kst, Pmax, and St classifications
- The overdriving effect in 20-liter testing
- 20-liter versus 1-m³ test vessels
- Interpreting low or weakly positive Kst results
- PVC resin types, particle size, and process-generated fines
- Representative sampling and laboratory test conditions
- ASTM E1226 and the 2012 PVC testing study
- Applying test results to Dust Hazard Analysis and explosion protection
- Limitations of St 0 conclusions and facility-specific assessments
Reactive Chemical Hazards & Process Scale-Up
Topics Covered:
- DSC screening
- ARC testing
- Reaction calorimetry
- Adiabatic testing
- VSP/DIERS
- Runaway reactions
- Thermal stability
- Process scale-up
- Emergency relief design
Electrostatic Ignition Hazards
Electrostatic ignition hazards can arise in processes involving combustible dusts, powders, flammable liquids, gases, and insulating materials. This section examines how electrostatic charge is generated, accumulated, and discharged, and explains why bonding and grounding alone may not eliminate every credible ignition mechanism. It also addresses the limitations of applying laboratory ignition data directly to plant conditions and provides an engineering framework for evaluating whether a specific electrostatic discharge can ignite a combustible atmosphere.
Topics Covered:
- Charge generation and accumulation
- Conductive versus insulating materials
- Bonding and grounding
- Isolated conductors and charged surfaces
- Spark, brush, and propagating brush discharges
- Minimum ignition energy (MIE)
- Powder resistivity and chargeability
- Liquid conductivity
- FIBC hazards
- Electrostatic hazards in powder and liquid handling
- Evaluating electrostatic discharge as an ignition source
- Distinguishing electrostatic ignition from other ignition mechanisms
- NFPA 77, ASTM E2019, and relevant IEC guidance
Hazardous Area Classification & Ignition Source Analysis
Topics Covered:
- NEC Class/Division, IEC Zones
- Gas and dust classification
- Ventilation
- IEC 60079, EN 1127-1, ISO 80079-36
- Non-electrical ignition sources
- Mechanical sparks, hot surfaces and electrostatic ignition
Self-Heating & Thermal Instability
Topics Covered:
- Air-Over-Layer
- Bulk Powder
- Aerated Powder
- Basket self-heating
- EN 15188
- Self-ignition temperature
- Scale-up, dryers, silos, hoppers, FIBCs and drums
Pressure Relief & DIERS
Topics Covered:
- Relief design basis
- Reactive systems
- Two-phase flow
- DIERS methodology
- VSP testing
- Runaway reactions
- Relief sizing assumptions
- Disposal considerations
UN/DOT Hazard Classification
Topics Covered:
- UN Test N.4 self-heating
- Division 4.1/4.2/4.3
- Packing Group II vs III
- Self-heating vs pyrophoric behavior
- Package-volume considerations
- N-/O-series testing