Using the PETS Toolbox Inventory Calculator

For licensed blas

For licensed blasters, explosive inventory is not optional — it is a regulatory requirement. Whether you operate under ATF regulations, state permits, or company internal controls, maintaining accurate monthly inventory records is critical for:

• ATF compliance
• Theft prevention
• Magazine inspections
• Insurance requirements
• Audit protection
• Professional accountability

To simplify this process, we built the Explosive Inventory Calculator inside the PETS Toolbox.

Why Monthly Inventory Matters

Under ATF 27 CFR Part 555, licensees and permit holders must:

• Maintain accurate acquisition and disposition records
• Conduct physical inventory checks
• Reconcile discrepancies
• Retain records for inspection

Failure to maintain accurate records can result in:

• License suspension
• Fines
• Project shutdown
• Criminal investigation in severe cases

Inventory is not just paperwork — it is part of your explosives safety system.

What the PETS Inventory Tool Does

The PETS Explosive Inventory Calculator helps blasters:

• Track beginning inventory
• Add new purchases
•  Subtract usage
• Account for transfers
• Calculate ending inventory
• Verify physical count matches records

It reduces manual math errors and standardizes documentation.

Step-by-Step: How to Use the PETS Inventory Tool

Step 1 — Enter Beginning Inventory

Start with the quantity recorded at the end of the previous month.

This should match your last documented physical count.

Step 2 — Enter Acquisitions

Add all explosive materials received during the month, including:

• ANFO
• Emulsion
• Dynamite
• Detonators
• Boosters
• Det cord

Always verify delivery tickets.

Step 3 — Enter Usage

Input all explosives used on blast sites during the month.

This should match:

• Shot logs
• Blast reports
• Daily use sheets

Consistency between field logs and inventory records is critical.

Step 4 — Enter Transfers (If Applicable)

If you transferred materials:

• Between magazines
• To another license holder
• Returned to supplier

Document it clearly.

Step 5 — Verify Ending Inventory

The PETS tool calculates:

Beginning Inventory

• Purchases
• – Usage
• ± Transfers
• = Expected Ending Inventory

Now compare this to your physical count.

What If Numbers Don’t Match?

Discrepancies must be investigated immediately.

Possible causes:

• Math errors
• Recording mistakes
• Product misclassification
• Field reporting delays
• Theft or diversion

Document corrective action. Never ignore a discrepancy.

Best Practices for Blasters

• ✔ Conduct inventory at the same time each month
• ✔ Count by product type and lot number
• ✔ Keep detonators separate in records
• ✔ Match magazine log to shot logs
• ✔ Maintain digital and paper backups
• ✔ Prepare records assuming ATF inspection

Professional blasters treat inventory like a safety tool — not paperwork.

Why PETS Built This Tool

At PETS (Practical Explosives Training School), we teach:

Safety = Documentation + Engineering + Field Discipline

The Inventory Calculator is designed to:

• Reduce risk
• Improve organization
• Support compliance
• Save time

Who Should Use This Tool?

• Licensed blasters
• Magazine keepers
• Quarry supervisors
• Construction contractors
• Oil & gas blasting crews
• Avalanche control teams
• Manufacturing facilities

If you handle explosives, monthly inventory is mandatory.

Final Reminder

Inventory errors are often discovered during inspections — not during blasting.

The safest way to operate is:

1. Count it.
2. Record it.
3. Verify it.
4. Document it.

Use the PETS Explosive Inventory Calculator to make the process faster and more reliable.