NFPA660 Standard: What Non-Ferrous Foundries Need to Know

The National Fire Protection Association (NFPA) has released NFPA 660 – Standard for Combustible Dusts and Particulate Solids, effective December 6, 2024. This new standard combines six older combustible dust standards into one, including NFPA 484 (Combustible Metals) and NFPA 652 (Fundamentals of Combustible Dust).

For nonferrous foundries producing castings in aluminum, copper alloys, magnesium, zinc, or other metals, NFPA 660 is especially important because it directly addresses combustible metal dust hazards and introduces new requirements that were not clearly spelled out before.

What’s New in NFPA 660

Here are the most significant changes affecting foundry operations:

1. Emergency Planning – Facilities must have a written plan for responding to dust-related fires or explosions, including assigned roles and employee training.

2. Interim Safety Measures – If full compliance can’t be achieved immediately, temporary risk-reduction measures must be put in place until upgrades are complete.

3. Risk-Based Housekeeping – Cleaning schedules must be based on where dust collects and how much hazard it presents, rather than on fixed intervals alone.

4. More Documentation – Facilities must keep a written combustible dust safety program, inspection logs, maintenance records, and training documentation.

5. Clearer Dust Testing Rules – NFPA 660 details which dust properties must be tested (like explosion pressure, ignition energy, and minimum explosible concentration) and requires using actual test results for your dust, not just industry averages.

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Why It Matters for Nonferrous Foundries

• Finishing operations such as grinding, cutting, polishing, and shot blasting of nonferrous metals may produce fine dust that might ignite or explode under the right conditions.

• Dust Hazard Analyses (DHA) must now be reviewed and updated at least every five years or whenever significant changes are made—outdated DHAs will no longer meet the standard.

• New requirements place stronger emphasis on proactive hazard control, housekeeping, and preparedness, not just compliance on paper.

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Practical Steps for Foundries

Even small foundries can take meaningful steps toward compliance:

• Review and update your DHA using accurate testing data for the dusts your processes generate.

• Develop a dust-specific emergency response plan and train your staff on it.

• Set housekeeping priorities based on risk areas and dust accumulation levels.

• Keep thorough records for inspections, cleaning, training, and equipment maintenance.

Bottom line: NFPA 660 unifies combustible dust safety requirements and raises the expectations for hazard control in non-ferrous foundries. By improving emergency readiness, risk-based cleaning, and documentation, foundries can better protect workers, facilities, and production continuity as defined within the NFPA 660 standard.