Bump Test Gas — Complete Guide for Gas Detector Safety Programs

Bump testing is one of the most important — and most commonly neglected — safety procedures for portable gas detector programs. This guide covers everything safety managers and EHS coordinators need to know about bump test gas: what it is, how often to do it, which gas to use for your specific detector, and how to set up an automatic supply program that ensures you never run out.

What Is a Bump Test?

A bump test — also called a function check or challenge test — is a quick procedure that exposes a portable gas detector to a known concentration of calibration gas to verify that:

•       Each gas sensor responds to the target gas

•       The detector triggers visible, audible, and vibration alarms at the correct threshold

•       The detector is functioning correctly before use in a hazardous environment

A bump test does NOT adjust the detector's sensor readings. It only confirms the detector responds. If the detector fails a bump test — meaning it does not alarm at the correct threshold — it must be removed from service and sent for full calibration or repair.

How Often Should You Bump Test Your Gas Detector?

This is the most common question in gas detection safety programs — and the answer depends on your regulatory environment, your industry, and your detector manufacturer's recommendations.

Bottom line: For any instrument used in confined space entry, HAZWOPER operations, or any environment that could be immediately dangerous to life and health (IDLH), bump test before every single use. No exceptions.

Bump Test vs. Calibration — Key Differences

Which Bump Test Gas Do I Need?

The bump test gas must match the gas sensors installed in your detector. For the most common 4-gas detectors measuring CO, H₂S, O₂, and LEL combustible gas, the standard bump test gas is the 380 mixture or its variants:

How to Set Up a Bump Test Auto-Replenish Program

Running out of bump test gas is a common and preventable problem. When a team exhausts their calibration gas supply, instruments cannot be verified before use — creating a compliance gap and a safety risk. The solution is an automatic replenishment program.

Step 1 — Calculate your monthly consumption

•       Count the number of detectors in your program

•       Multiply by your bump test frequency (daily, weekly, or per-use)

•       Each bump test uses approximately 0.1-0.2 liters of gas

•       Divide total monthly liter consumption by your cylinder size

Step 2 — Choose your cylinder size and delivery interval

•       17L-380: good for 1-2 detectors bumped daily — replace every 30-60 days

•       34L-380: good for 3-5 detectors bumped daily — replace every 30-60 days

•       58L-380: good for 6-10 detectors bumped daily — replace every 30-60 days

•       103L-380: good for 10+ detectors or teams with multiple instruments

Step 3 — Set up Auto-Replenish with Trigas USA

•       Visit trigasusa.com/subscribe and select your mixture and cylinder size

•       Choose delivery frequency: every 30, 60, or 90 days

•       Receive 8% discount on every order plus free shipping

•       Get automatic reminder email 14 days before delivery

•       CoA and SDS included with every shipment for audit documentation

Bump Test Documentation — What to Record

OSHA and industry best practices require documentation of bump tests for confined space entry and HAZWOPER programs. At minimum, record:

•       Date and time of bump test

•       Instrument serial number and model

•       Calibration gas cylinder lot number and part number

•       Pass / Fail result for each sensor

•       Name of person performing the test

•       Action taken if instrument failed (removed from service, sent for calibration)

Trigas USA provides digital CoA documentation for every cylinder. The cylinder lot number on your CoA links back to our ISO 17025:2017 laboratory records — creating a complete, auditable traceability chain from your bump test record back to NIST measurement standards.

ISO/IEC 17025:2017 (L25-1002) · ISO 17034:2016 (L25-1003) · EPA PGVP #29 · PJLA #125017