Lives, research, and expensive equipment are at stake

Dust, grime, and bacteria can gather on fire sprinkler heads, out of sight and often out of reach during a typical cleaning. The Joint Commission, a nonprofit organization that accredits and certifies tens of thousands of hospitals in the United States, penalized nearly two in five hospitals for dirty or damaged fire sprinkler heads in the first six months of 2017. And in the immaculate environments used by the makers of sensitive microelectronics and healthcare products – where cleanliness is measured by the particle – the fight against contamination enlists every process, fixture, and feature.

To see how concealed fire sprinklers are an affordable defense against multi-million-dollar contamination in ultra-clean environments, read on.

Loaded sprinkler head

Dust causes a fire sprinkler head to become “loaded,” which can cause a malfunction. Image source: Sprinkler Age

How clean is clean?

Cleanrooms are controlled environments used in industries where even microscopic levels of dust, living organisms, particles, or other contaminants could ruin products or research – or harm people.

A dust particle on the end of a pencil’s eraser is as small as a ladybug in a 50,000-person stadium (maybe smaller). How many would you find in the world’s most rigorously-made cleanrooms?


In these environments, every decision and aspect of design counts. Cleanliness isn’t just about the walls, floors, and ceilings, but also the outlet covers, the kinds of pen and paper used, and even the cleanliness of nearby rooms.

But cleanrooms, like any other industrial space, aren’t exempt from fire safety. And at a cost of $1,500 per square foot or more to construct some of the most basic cleanrooms, it’s critical to have a fire sprinkler system that’s both functional and helps keep the space contaminant-free.

The cost of stray particles

While the costs of cleanroom construction are high, the cost of contamination is often much higher.

Cleanrooms are classified by the International Standards Organization (ISO) according to the level of cleanliness required.

A Class 2 space might be ideal for photolithography – a process used in circuit boards and other small electronics – because it allows for no more than a few dust-sized particles in every square meter of air. A Class 8 space might serve as the buffer between these zones and the outside world, providing some filtration but still leaving tens of millions of large particles airborne.

If these standards seem rigorous, it’s because the cost of error can be enormous. For pharmaceutical companies, failing to observe these standards can lead to fines and product recalls. A fungus found in drugs sold by the New England Compounding Center caused hundreds of brain infections in 19 states, including nearly 70 fatal incidents.

In 2006, Apple recalled almost two million batteries. Microscopic metal particles led to electronic failures, setting off a chemical chain reaction that made batteries overheat and, in some instances, catch fire. The recall cost the company as much as $258 million dollars.

Sanitary design and fire sprinklers

Cleanrooms and other environments where cleanliness is critical are constructed from materials that are durable, easily cleaned, abrasion-resistant, and can withstand harsh chemicals used to eliminate contamination. Typically, that includes materials like stainless steel, anodized aluminum, and polymer coatings.

To limit contamination from outside spaces, the cleanroom structure must be airtight. Sprinkler heads should intrude as little as possible into sanitary spaces and minimize the potential for leaks. Openings are required for light fixtures, piping, wiring, and sprinkler heads, but each should be sealed, and every mechanism should be suitable for frequent cleaning.

Regularly cleaning the most common sprinkler heads – such as the pendent head pictured below – can be a problem.

Different fire sprinkler heads

The irregular shape of a pendent head (top right) is more difficult to clean than concealed solutions, which have a single, smooth surface (bottom right). Image source: Pinterest

In an earlier blog, QRFS explained the right way to clean a fire sprinkler head using pressurized air and/or a vacuum. To prevent damage to the head and avoid accidentally activating the sprinkler, it’s critical that the head not be touched.

While this might work well in an office or a warehouse, every surface in a cleanroom environment likely requires chemical cleansing on a regular basis. For ultra-sanitary spaces, the key is choosing a sprinkler that won’t discharge or get damaged when you clean it.

Cleanroom sprinkler covers

Concealed head sprinklers simply hide the sprinkler head behind a cover plate.

Just like the sprinkler itself, the cover plate is designed to detach at a specified temperature, allowing the head beneath to deploy and extinguish the fire. Concealed fire sprinklers have a smooth surface, providing the same level of fire safety with a surface that gathers less dust and cleans more easily.

If you’ve already got cover plates in your sanitary space or cleanroom, remember: Each concealed fire sprinkler has only one replacement cover plate. If you’re looking to replace yours, please click on this guide to help you find the right one.

At QRFS, we offer replacement cleanroom cover plates for Reliable’s Model G4, G4A, and G5 sprinklers. The G5’s cover plates are sold with a gasket that limits the movement of dust, air, and water through the ceiling, and the model can be plated with the same Type 316 stainless steel often used in pharmaceutical cleanrooms.

At $25 each, cover plates provide a simple, cost-effective, and time-saving solution to the problem of dirty sprinkler heads in ultra-sanitary spaces.

Click here to order a reliable cleanroom cover plate.

If you have any questions about cleanroom cover plates or any other fire safety solution, give ORFS a call at 888.361.6662 or fill out our contact form.