Farewell to Mercury Lamps: “Later” Has Arrived

In most security printing and hologram plants there is at least one machine that “only runs properly” on a mercury lamp.

The lamp has more hours on it than some of your operators. No one is entirely sure where the RoHS file is. Purchasing has a quiet stash of spare lamps, bought “just in case”, and everyone pretends this is a plan.

Regulators, sadly, do not share the joke.

Across Europe and the UK, RoHS updates have already banned most general-lighting fluorescent lamps from sale. The remaining exemptions for specialist UV and discharge lamps now come with expiry dates, several of them before or around 2027. At the same time, the Minamata Convention on Mercury is pushing governments to phase out mercury-added products where modern alternatives exist.

No one is going to storm your factory and remove lamps by force. They simply become harder to source, on longer lead times, at less amusing prices. That is not a theoretical risk if your holograms, microlens films or tax stamps depend on them.

What this actually means on the shop floor

In our corner of the world, mercury lamps still do useful work:

• curing nano-imprinted resins on PET and speciality films

• running step-and-repeat recombiners for holographic and micro-optical masters

• driving high-speed roll-to-roll UV casting for foils, labels and tax stamps

The impact of the ban is not philosophical. It is practical.

First, supply risk becomes real. A recombiner stopped because a lamp failed and the only replacement is “ten weeks, if we are lucky”, is not a conversation you wish to have with a central bank or tax authority.

Second, the chemistry has to move with the light source. Resins tuned to the broad mercury spectrum do not behave the same under a narrow LED band. Cure speed, shrinkage, stress and even demoulding can change. Sometimes the effect is subtle. Sometimes it is an unexpected new optical feature you did not design.

Third, your customers will start to ask questions with a straight face. “What is your plan to remove mercury from production?” shifts from polite ESG small talk to a pre-qualification tick box.

Light source, chemistry and mechanics are one system. Change one, and the others follow, whether you like it or not.

The four favourite excuses

Most of us have tried at least one of these:

1. “We have plenty of spare lamps.” That is borrowed time, not a strategy. They will never be cheaper than they are today.

2. “Our process is special. LEDs will never match it.” This sounded convincing in 2008. Today, high-intensity LEDs, tailored photoinitiators and hybrid systems are already curing demanding optical and security structures.

3. “We will upgrade when the machine dies.” These machines are annoyingly robust. You may find yourself with a perfectly sound line and no legal way to feed it lamps.

4. “Customers are not asking yet.” They will. First gently, then as policy. It is more comfortable to answer when you are already moving.

These are not reasons. They are polite delays.

A calm roadmap, rather than a 2027 panic

You do not need drama. You do need a list.

• Count your mercury users. Identify every system, from recombiners to lab coaters and forgotten exposure boxes. Note lamp type, hours, spare stock and revenue impact.

• Prioritise. Move first on high-revenue lines, equipment near end of life and processes with tight windows or exotic substrates.

• Choose the right upgrade path. Short term, better lamps and power supplies to buy time. Medium term, LED or hybrid retrofits on existing bases. Long term, new platforms designed around LED (and, where useful, excimer) from the start.

• Re-engineer the resin. This is where UV suppliers earn their keep. Photoinitiators, viscosity, shrinkage and optical performance all need checking under LED. A proper, statistically designed set of trials is cheaper than field failures.

• Turn compliance into a sales story. Mercury-free curing is easy for your customer to explain to auditors, boards and ministers. It improves energy use and removes an obvious environmental irritant.

Turning a ban into an advantage

No one wakes up eager for regulatory change. It lives in the same emotional drawer as dental appointments and printer error messages.

Yet for security printers and optical film makers, the end of mercury lamps can:

• cut energy and maintenance costs

• tighten process windows and improve replication fidelity

• justify modernising ageing equipment and controls

• provide a credible, concrete ESG improvement

The ban is coming whether we approve of it or not. The only useful choice is whether we arrive at that future ready, with LED-optimised processes and equipment, or slightly out of breath, clutching the last surviving box of mercury lamps and hoping no one notices.

By Guri Dhillon Co-Founder, XRD Nano Limited

About XRD Nano XRD Nano is a London-based engineering company developing UV nanoimprint equipment and advanced chemistries that make it easier to manufacture better optical films for anticounterfeiting and holographic industry with less drama on the production line.

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