Combustible dust

This module registers combustible-dust hazard areas under NFPA 652/654 — classifying each by its Kst deflagration index (St class), tracking the Dust Hazard Analysis reevaluation interval, and watching housekeeping accumulation against the layer/coverage threshold.

Register a dust hazard area

1. In the Register a dust hazard area form, pick the site and name the area and material.
2. Enter the Kst value (bar·m/s) — the module assigns the St class: St0 (0, tested non-explosible), St1 (up to 200), St2 (up to 300), St3 (above 300).
3. Set the DHA completed on date and the reevaluation interval in years (defaults to the NFPA 652 five-year cycle), then click Register area.

Read the register

• Each area shows its Kst, an St class badge (green St0, red St3), and the DHA due date with an overdue flag when the analysis is past due.
• The housekeeping column flags an area as a hazard when its latest recorded dust accumulation crosses the threshold — a layer of roughly 1/32 inch (0.8 mm) over 5% or more of the floor area, per the OSHA combustible-dust NEP threshold.
• Rows needing attention are highlighted red. Non-explosible (St0) areas never flag.

Record a housekeeping check

• Click Housekeeping… on an area to log the latest dust accumulation: enter the layer depth (mm) and the floor coverage (%), then Save. The reading trips the accumulation hazard once it crosses the NFPA/OSHA threshold — a layer of roughly 1/32 inch (0.8 mm) over 5% or more of the floor area — and clears it once a follow-up check comes back under.
• When an area's DHA is overdue, a DHA re-evaluated button appears; click it to record a completed Dust Hazard Analysis reevaluation as of today, which rolls the next due date forward.

Follow up

• For any area needing attention, click CAPA to open a corrective action — a fresh DHA or a housekeeping cleanup — and the row then links to that CAPA.
• Decommission an area that's permanently removed: it leaves every attention count while its history stays.
• Export register CSV downloads the NFPA 652 dust-area register — St class, DHA status, and housekeeping state — from api/combustible-dust/register.csv.

What happens automatically

• The daily escalation sweep notifies the safety team about every explosible area whose DHA is missing or past its reevaluation date.
• Every area over the housekeeping threshold also escalates — "Dust accumulation hazard: (area)" — until a follow-up check records the area back under the layer/coverage limit. A new observation re-notifies; the same standing accumulation doesn't pile up duplicates.
• The dashboard counts dust hazard areas, DHAs missing or overdue, and accumulation hazards.

Tip: St class is only as good as the Kst you enter — use a lab-tested value for the actual material, since assumed numbers can badly understate the explosion risk.

Related

• Hot work permits — Control the ignition sources near dust
• Process safety (PSM) — Broader process-safety management for covered processes
• Chemicals & SDS — Chemical hazard data for combustible materials
• CAPA (corrective & preventive actions) — Drive housekeeping and DHA gaps to closure