Lockout / Lock-Off Padlocks – What You Need to Consider
Lockout / Lock-Off Padlocks – What You Need to Consider
Padlocks used to lock electrical switches, machinery and access panels during maintenance are commonly known as lock-out, lock-off or tag-out padlocks. Their purpose is to prevent equipment being switched on or accessed while someone is working on it. To choose the correct lock, there are a few key factors to consider so that users, safety protocols and site requirements are all met.
Colour Coding and Marking
If you have multiple switches, cabinets or plant areas, being able to identify the correct lock at a glance is important. Many safety padlocks are available in bright colour options so different zones or purposes can be colour-coded (e.g. Red = Locked Out, Blue = Supervisor Use, Yellow = Maintenance). Sequential engraving or printed numbers can also help track locks and keys. Some organisations, such as utility companies and the National Grid, also colour-code key levels and engrave the lock body for clearer control. This prevents the wrong person using the wrong lock and improves audit trails.
Custom Key Systems
In many workplaces, different personnel require different access levels. For example: A “red” lock may only open with a specific key for a maintenance team, while a “blue” key may open both internal cabinets and external access doors. This is known as a keyed hierarchy system. To create this type of setup, you need padlocks that are service-built (not moulded), meaning they can be assembled to your exact key configuration. The ABUS 74 series and Eterna lockout ranges are custom-buildable in European workshops, meaning replacements can be made quickly when needed.
How Many Keys Do You Need?
Most general padlocks come with 2–3 keys. However, for lock-out situations, many workplaces require 1 key per lock to avoid spare keys going missing or being used incorrectly. If a worker locks off a machine, they should be the only person with the key. If you require 1 key per lock, ensure you choose a lock specifically supplied this way — otherwise removing spares from large orders becomes time-consuming.
Key Differ Variations (Security in Numbers)
Key variation is critical in safety environments. If key codes repeat too frequently, different locks may be opened with the same key — which is a serious safety risk. Cheaper padlocks may only have around 250–500 key differs. For industrial lock-out protocols, systems often require 1,000+ differs or guaranteed non-duplicates. The ABUS 74 series offers high differ counts, and Guaranteed Differ systems can be hand-recorded if absolute control is required. This allows you to expand your system later without duplication.
Anti-Spark and Non-Conductive Options
Electrical lock-out often requires non-conductive materials to prevent accidental shocks. The Masterlock Zenex series features insulated bodies, while certain versions of the ABUS 74 also include insulated shackles. In environments with flammable gases, fuels or chemicals, brass padlocks are sometimes used as a low-spark risk option. However, brass padlocks cannot usually meet the high differ counts of custom lockout systems, so suitability depends on the environment.
Summary
A proper lock-out system needs more than “just a padlock.” Consider colour coding, keying systems, differ count, replacement management and the environment where the lock will be used. A well-designed system improves safety, prevents downtime and ensures lock-out procedures are respected.