Examining the role cleanroom furniture plays in effective particle management to support efficient risk management in aseptic manufacturing. Written by Sue Springett
When your primary aim is to achieve and maintain an ultra-sterile, ISO-14644 compliant manufacturing environment,free from contamination caused by harmful bacteria, everything startswith effective particle management. And when you're measuring particles in fractions of microns, only an obsessive approach to cleanliness and contamination control will suffice.
Because harsh sterilisation methods have become standard in pharmaceutical and micro-biological manufacturing environments, cleanroom furniture has to be designed and manufactured to withstand the toughest of cleaning SOPs: mitigating the risk of rouging ortiger stripes while reducing contamination risk and supporting improved clean down productivity.
Cleaning chemicals such as chlorine and hydrogen peroxide can significantly reduce the lifespan of furniture built from 304-grade stainless steel, corroding and pitting the surface over time and increasing the risk of particles being released into the atmosphere.
Therefore, we would always recommend that clients specifying furniture for environments where abrasive chemicals are used on a regular basis opt for furniture manufactured from 316-grade stainless steel. That’s because 316-grade stainless steel, alongside chromium and nickel, includes molybdenum, a naturally occurring element which has one of the highest melting points of all elements. It improves the corrosion resistance of the stainless steel and has a strong positive effect on pitting and crevice corrosion resistance in chloride-containing solutions.
Any abrasive contact could cause particles to be released into the atmosphere and pose a risk to hygiene
As well as the type of stainless steel used to manufacture cleanroom furniture, another major consideration when specifying equipment is its finish or surface smoothness.
Surface smoothness is measured in Ra. Ra is the arithmetic average of the absolute values of the profile height deviations from the mean line recorded within the evaluation length. More simply, it is the average of a set of individual measurements of a surface’s peaks and valleys. When harsh chemicals are used to clean stainless steel furniture, they can pool in these microscopic valleys on coarser surfaces if not thoroughly removed with IPA wipes. Over time, the trace amounts of these chemicals will corrode, stain and contaminate the passive layer of the stainless steel.
As well as impacting on sterilisation and chemical management surface roughness also plays an important role in determining how an object will interact with its environment. An ultra-smooth finish will be less abrasive; preventing friction between furniture and any surfaces it may come into contact with, such as gloves or equipment. Any abrasive contact could cause particles to be released into the atmosphere and pose a risk to hygiene.
But as well as the material it is manufacturedfrom, the way that furniture is designed and positioned in a cleanroom can help or hinder your contamination control. If furniture has an ultra-smooth finish it will be easier to clean but inherent flat edges, grooves and ridges will provide a barrier to the effective removal of bacteria and the cleaning chemicals used to dispose of them.
If you opt for modular or mobile furniture, it's vital to ensure it is sufficiently robust. Does it offer the stability and firm platform you require for any new equipment you’ll be bringing in?
Consider a tall storage cabinet with a flat top. Firstly, it will be hard to reach for cleaning and secondly the level surface will allow liquids to sit and pool, rather than naturally running away. Look closely at the furniture in your sterile spaces to see if it is contributing to effective particle management or, in fact, hindering it.
Whilst your HVAC system might work well in terms of circulating air effectively around your space, a poorly chosen or sited piece of furniture can interrupt essential air flow,causing dead air spaces which will have a negative and dangerous effect on air circulation and microbe behaviour.
For example, if it has a solid back panel, a seemingly innocuous workbench will immediately create a barrier for ventilation.However, by switching from solid to perforated or slatted materials at the back of the workbench, dirt particles can disperse safely to mitigate risk. Similarly, a second shelf below should never be solid. Instead, opt for a series of bars as a shelf to allow maximum air flow andenable particles to move freely.
Ensuring that there is sufficient space around equipment so that air does not stagnate is something that should always be considered. Even chairs with solid backs can create blockages or still areas if poorly sited in relation to vents. When planning how your cleanroom will be used, take time to accurately predict where the windbreaks will be and how they can be mitigated. And what about your people? The single biggest risk to hygiene in cleanrooms and laboratories is humans and the10 grams of skin we each shed every day. But humans present another risk in terms of their impact on airflow. A person working in the wrong place for an extended period can cause airflow blockages and affect the hygiene of a cleanroom. So, when configuring your sterile workspace, consider how both your furniture and your people may impact on the airflow and the aseptic environment.
Every piece of furniture in a cleanroom should be specified with ISO-14644 in mind. And it is often the small details that make a huge difference. Every corner of your cleanroom should allow for easy access by your expert cleaning team. Is there sufficient space between the floor and base of units, as well as around the sides, for thorough cleaning access? Can you move the furniture to access all areas and carry out deep cleans?
If you opt for modular or mobile furniture, it's vital to ensure it is sufficiently robust. Does it offer the stability and firm platform you require for any new equipment you’ll be bringing in? When working with hypersensitive weights you cannot afford any movement or ‘judder’ from your furniture. At Teknomek we have been advising our customers on achieving superior hygienic environments for more than 35 years, creating bespoke solutions for ultra-sterile environments and responding to the changing needs of the pharmaceutical and microbiological sectors.
On 25 May 2022, we launched our first ever product range designed entirely to support aseptic environments. Hygienox, from Teknomek, which has been more than two years in research and development, brings together furniture and equipment specially designed for ultra-sterile manufacturing spaces where ISO14644 is front of mind. Major investment in research, development and design has gone into all products in the new Hygienox range to ensure that every element of every product can withstand the harshest of chemical cleaning procedures. For example, because off-the-shelf solutions available were not up to the meticulous Hygienox standards, our pastors have been specially commissioned to include a chemical resistant polypropylene wheel inside a 316-grade stainless steel body.
With Hygienox we have created a range designed to revolutionise the sterile manufacturing market and set a new benchmark in performance. As well as 316-grade stainless steel furniture manufactured in-house, the Hygienox, from Teknomek range will feature other, specially selected and specified products designed for ultra-sterile environments where ISO 14644 compliance is non-negotiable. Hygienox from Teknomek has been developed to provide a completely elevated range that offers our customers best in class products when they need them.