How to Inspect & Maintain Insulated Tools for Long Life (and Safety)

When working on the UK’s electrical network, your hand tools are an essential piece of safety equipment. At Insulated Hand Tools, we’ve spent the last 44 years supplying high-end, ISO 60900 certified gear to the DNO sector and electrical subcontractors.

We know that buying a quality tool is only half the job. Once that screwdriver or pair of pliers goes into your kit bag, it gets knocked about, exposed to the weather, and covered in grime. To make sure your tools keep protecting you from live currents, you need a straightforward, regular maintenance routine.

Read on for our practical guide on how to inspect, clean, and store your insulated tools to keep them safe and extend their working life.

Why ISO 60900 Certification Matters

If you work in the electrical trade, you’ll see the ISO 60900 and VDE symbols on your tools. But what do these marks actually mean for your day-to-day work?

Tools with this certification aren’t just dipped in standard plastic. They are made using special materials that block electricity. To get the certification, every single tool is tested in a water bath with a 10,000-volt charge running through it. Because they pass at 10,000V, they are certified as safe to use on live circuits up to 1,000V AC.

That gives you a massive safety margin. However, that safety margin only exists if the plastic coating is in perfect condition. Even a tiny pinhole can let moisture in and create a path for the electricity to reach your hand. When you inspect your tools, you are simply checking that this protective layer is still fully intact.

How Dual-Layer Insulation Works

Many of the high-quality insulated tools we supply feature dual-layer, or multi-colour, insulation. This is a very clever, simple design feature to help you spot damage quickly.

Usually, the tool will have a bright outer layer (like red or orange) and a different inner layer (often yellow).

• The Outer Layer: This is your main protection against electricity and everyday knocks and scrapes.
• The Inner Layer: This is your visual warning system.

If you are looking at your cable cutters and you can see a spot of yellow showing through the red handle, the tool is no longer safe. The outer protection has worn through, and the tool needs to be binned.

Pre-Use Visual Inspection: What to Look For

Checking your tools shouldn’t be a monthly chore; it needs to be a quick habit you do every time you take a tool out of your bag. Here is exactly what you should be looking for.

1. Checking the Handles and Insulation

Hold the tool and give it a good look over. You are looking for anything that breaks the surface of the plastic.

• Cuts and Scratches: Run your thumb over the handles. You will often feel a deep slice – perhaps caused by a stray Stanley knife in your tool bag – before you see it.
• Cracks: Look closely at the neck of the tool, where the plastic meets the bare metal. This area takes a lot of twisting force. If the plastic looks like it has tiny spiderweb cracks, it is starting to fail.
• Burn Marks: If the tool has scorch marks from extreme heat or a previous electrical arc, the plastic is ruined and will not protect you properly.
• Swelling or Stickiness: If the handles feel spongy, bloated, or sticky, they have probably come into contact with a chemical like oil or hydraulic fluid that is eating away at the plastic.

2. Checking the Metal Parts

A tool with perfect insulation is still dangerous if the metal working parts are worn out.

• The Tips and Edges: Check your screwdrivers to make sure the tips aren’t rounded off, which causes them to slip out of screw heads. Make sure the cutting edges of your pliers are sharp and haven’t got chunks missing.
• Loose Joints: Pliers and cutters should open and close smoothly. If the joint is loose and wobbly, the tool might twist when you grip something hard, which can crack the plastic insulation around the handles.
• The Grip: The plastic insulation should be tightly stuck to the metal underneath. If you can twist the plastic handle independently of the metal shaft, moisture can get trapped inside.

3. Checking for Dirt and Moisture

Dirt and water conduct electricity. Even if the plastic handles are in perfect condition, a streak of wet mud or metallic dust running from the bare metal tip down to your hand can carry a current straight past the insulation. Make sure the tool is completely dry and clean before you use it on a live board.

Cleaning and Storing Your Tools Properly

The weather and the environment on UK sites can be harsh. Taking a couple of minutes to look after your tools at the end of the day makes a huge difference to how long they last.

The Right Way to Clean Your Tools

The plastics used on insulated tools are quite sensitive. If you use the wrong cleaner, you can make the plastic brittle, meaning it might crack the next time you drop it.

• What to use: Keep it simple. A clean, dry cloth is usually enough to wipe away dust. If they are very dirty, a cloth slightly dampened with mild soap and water is fine. Just make sure you dry them properly straight away.
• What to avoid: Never use harsh chemicals like brake cleaner, acetone, petrol, or strong degreasers. These will eat into the plastic. The tool might look clean, but the insulation will be weakened.

The Best Way to Store Your Tools

Throwing an expensive insulated screwdriver into a metal toolbox mixed in with loose drill bits, hammers, and saws is a guaranteed way to ruin it.

• Keep them separate: Insulated tools should be kept in their own tool roll, a foam-lined box, or a dedicated pouch. This stops them getting sliced or dented by other tools while you are driving between jobs.
• Watch the temperature: Try not to leave your tools sitting on the dashboard in the blazing sun, or locked in a freezing van for days on end if you can avoid it. Extreme hot and cold temperatures cause the metal and plastic to expand and contract at different rates, which can loosen the grip.
• Keep them out of the sun: Leaving tools in direct sunlight for long periods will cause UV damage. The plastic will fade and eventually become brittle.

Pass vs. Fail: When to Replace Your Tools

Nobody likes throwing away a good, expensive tool. But when you weigh the cost of a new pair of pliers against the risk of an electric shock, it is an easy choice. Use this simple checklist to decide if a tool is safe for work.

What to Check	Pass (Safe to Use)	Fail (Replace Immediately)
Outer Plastic	Smooth, even colour, no deep scratches.	Cuts, cracks, deep gouges, or you can see the inner coloured layer.
Metal Head	Tight, no rust, sharp edges, good tips.	Loose, heavily rusted, bent edges, rounded tips.
Safety Marks	ISO 60900 / VDE symbols are easy to read.	Symbols are completely rubbed off.
Feel of the Handle	Firm grip, completely dry.	Spongy, sticky, or bloated plastic.
Cleanliness	Free of oil, grease, and metal dust.	Covered in grime that won’t wipe off safely.

A quick note on repairs: You cannot repair an insulated hand tool. Wrapping a cut handle in electrical tape or covering it in superglue does not make it safe for 1,000V work. If a tool fails the checks above, you should physically break it (for example, by cutting the handle off) before you throw it in the skip. This ensures nobody else can pick it up and use it by mistake.

A Final Thought on Safety

After more than 40 years in the industry, we know that doing the same job every day can make people a bit relaxed about safety. When you’ve worked on live cables hundreds of times without an issue, it’s easy to assume you’ll be fine the next time.

But damaged tools don’t care how much experience you have. A small crack in the handle can lead to a serious injury. By taking a few seconds to check your kit, keeping it clean, and storing it properly, you protect yourself and the network.

Did Your Kit Fail the Inspection?

Never compromise on electrical safety. If your daily check has revealed a cracked handle, a chipped tip, or an exposed warning layer, that tool must be taken out of service immediately.

At Insulated Hand Tools Ltd, we have spent over 40 years keeping the UK DNO sector and electrical subcontractors safe. When it is time to cycle out damaged gear, we provide the highest quality ISO 60900 and VDE certified replacements to get your kit bag back up to standard.

Whether you prefer the virtually indestructible injection-moulded ITL Nylon 11 range or traditional dual-colour dipped PVC tools, we have the exact equipment you need, ready for the network. Shop All Our ISO 60900 Insulated Tools Here.

Disclaimer: This blog post provides general information on electrical safety and tool standards. Always refer to specific site procedures, risk assessments, and relevant regulations (such as the UK’s Electricity at Work Regulations 1989). Seek expert advice for your particular situation. Safe work practices should always be determined by qualified personnel.