Across the United States, fire departments are increasing enforcement of hazardous materials storage requirements. One of the most common requests facilities now receive is for a Hazardous Materials Inventory Statement (HMIS) — a detailed document required under the International Fire Code (IFC) and National Fire Protection Association (NFPA) standards.

Unfortunately, most facilities struggle to prepare an HMIS correctly. Errors in hazard classification, quantities, storage locations, or CAS numbers can lead to failed inspections, fines, or even operational shutdowns.

This guide walks you through how to prepare an HMIS accurately, avoid common mistakes, and ensure your facility is ready for fire department review.

What Is an HMIS and Why Is It Required?

An HMIS is a standardized document that lists all hazardous materials stored or used at a facility. Fire departments use HMIS documents to:

• Evaluate compliance with Maximum Allowable Quantities (MAQs)
• Assess fire and life safety risks
• Plan emergency response
• Verify proper storage and segregation
• Ensure accurate hazard classification

If your facility stores flammable liquids, corrosives, oxidizers, compressed gases, toxics, or other regulated materials, you are required to maintain an HMIS.

Why HMIS Requests Are Increasing in 2026

Several trends are driving increased enforcement:

• Fire departments are conducting more frequent inspections
• Insurance carriers are requiring updated hazardous materials documentation
• Warehouses and distribution centers are storing more chemicals than ever
• IFC/NFPA updates emphasize MAQ compliance
• Emergency responders need accurate hazard information

Many facilities are caught off guard when inspectors request an HMIS — especially if they have never prepared one before.

What Your HMIS Must Include

A compliant HMIS typically includes:

1. Chemical Name

Use the exact name from the SDS. Avoid abbreviations or trade names unless they are the only identifier.

2. CAS Number

This ensures accurate hazard classification. Missing or incorrect CAS numbers are one of the most common HMIS errors.

3. Hazard Class

Hazard classes must follow IFC/NFPA definitions, not OSHA or DOT categories. Examples include:

• Flammable Liquid
• Corrosive
• Oxidizer
• Toxic
• Pyrophoric
• Combustible Dust

4. Physical State

Solid, liquid, or gas.

5. Quantity

List the maximum quantity onsite, not average or typical amounts.

6. Storage Location

Include:

• Building
• Room
• Area
• Control area designation

7. Container Type

Examples:

• Drums
• Totes
• Cylinders
• Tanks
• Bottles

8. Storage Conditions

Such as:

• Temperature control
• Ventilation
• Separation requirements
• Fire protection features

9. SDS Reference

Fire departments often request SDS copies for all listed materials.

How to Gather Accurate HMIS Data

Preparing an HMIS requires a systematic approach. Here’s how to do it correctly.

Step 1: Conduct a Physical Inventory

Walk the facility and document:

• Every chemical
• Every container
• Every storage location
• Every quantity

Do not rely solely on purchasing records — they are almost always incomplete.

Step 2: Collect SDS Sheets

Ensure SDS sheets are:

• Current
• Complete
• From the manufacturer
• Matching the product onsite

Outdated SDS sheets lead to incorrect hazard classifications.

Step 3: Verify Hazard Classifications

Use IFC/NFPA hazard classes — not OSHA or DOT categories.

For example:

• OSHA “flammable” is not always IFC “flammable liquid”
• DOT “corrosive” may not meet IFC corrosive thresholds
• NFPA oxidizer classifications differ from DOT oxidizer classes

Misclassification is the #1 reason HMIS documents are rejected.

Step 4: Calculate Maximum Allowable Quantities (MAQs)

MAQs determine how much hazardous material you can store in each control area.

You must consider:

• Sprinkler protection
• Storage type (open vs. closed)
• Occupancy type
• Fire barriers
• Floor level
• Hazard class

If your quantities exceed MAQs, you must:

• Add fire barriers
• Reduce quantities
• Relocate materials
• Change storage methods

MAQ violations are a major enforcement focus in 2026.

Step 5: Prepare Storage Maps

Fire departments often require:

• Floor plans
• Storage area diagrams
• Control area boundaries
• Hazard class locations
• Tank and cylinder locations

Maps must be clear, accurate, and easy to read.

Step 6: Assemble the HMIS Document

A complete HMIS package includes:

• HMIS table
• SDS sheets
• Storage maps
• MAQ calculations
• Contact information
• Emergency response details

Caltha typically prepares HMIS documents as a single organized package for inspectors.

Common HMIS Mistakes (and How to Avoid Them)

1. Incorrect Hazard Classification

Using OSHA or DOT categories instead of IFC/NFPA.

2. Missing CAS Numbers

Fire departments require CAS numbers for verification.

3. Quantities Not Matching Physical Inventory

Inspectors will check actual quantities onsite.

4. Outdated SDS Sheets

SDS sheets must match the product and manufacturer.

5. Missing Storage Maps

Maps are required for emergency response planning.

6. Incorrect MAQ Calculations

MAQs are complex — many facilities miscalculate them.

7. Using Trade Names Instead of Chemical Names

Trade names often hide the true chemical identity.

8. Not Updating HMIS After Inventory Changes

HMIS must be updated whenever materials change.

How Caltha LLP Helps Facilities Prepare HMIS Documents

Caltha provides full HMIS preparation services, including:

• Facility walkthroughs
• Hazardous materials inventory development
• SDS verification
• IFC/NFPA hazard classification
• MAQ calculations
• Storage map creation
• Complete HMIS document assembly
• Fire department liaison support

Most facilities discover significant compliance gaps during HMIS preparation — and correcting them prevents costly enforcement actions.

Conclusion

Preparing an HMIS correctly is essential for fire code compliance, emergency response planning, and safe facility operations. With enforcement increasing in 2026, facilities must ensure their hazardous materials documentation is accurate, complete, and aligned with IFC/NFPA requirements.

A professionally prepared HMIS not only satisfies fire department requests but also reduces risk, improves safety, and strengthens overall compliance.

Need further technical assistance with your HMIS?

If your facility needs help preparing an HMIS or evaluating hazardous materials storage, Caltha LLP can assist with inventory development, MAQ calculations, storage maps, and full HMIS documentation. Contact us to schedule a hazardous materials assessment.