Effectiveness of decontaminating mats
Does a contamination control mat really make a measurable difference? A laboratory study commissioned by HelloMat investigates how effectively a HelloMat washable contamination control mat removes particles and fibres from shoe soles under controlled test conditions.
Every day, people, carts and mobile equipment move through controlled environments carrying microscopic particles, fibres and microorganisms on their shoe soles and wheels.
Contamination control mats are widely used to reduce this transfer, but one important question remains: what is the actual effectiveness of decontaminating mats under realistic operating conditions?
To answer this question, an independent laboratory evaluated the particle removal performance of a HelloMat washable contamination control mat using microscopic particle counting techniques after only three steps across its surface.
The results provide valuable insight into how contamination is progressively reduced before particles and fibres can be transferred into critical areas.
Why Does This Matter?
Floors are not the main source of contamination, but they are one of its primary transfer routes. As personnel and equipment move throughout a facility, contaminants deposited on the floor can adhere to shoe soles and wheels before being transported into cleaner environments. Once transferred, these contaminants may settle on new surfaces or continue moving through the facility.
Among the contaminants that can be transferred at floor level are:
Fine dust particles
Synthetic particles
Dust and debris
Textile and paper fibres
Hair and skin flakes
Powder residues
Microorganisms, including bacteria and fungal spores
Reducing this transfer at the point of entry is one of the most effective ways to support contamination control strategies.
Looking Closer: The Laboratory Test
To evaluate the effectiveness of the washable contamination control mat, the analysis was carried out by an independent laboratory using adhesive tape lift sampling followed by optical microscopy.
Rather than assessing only visible dirt, the study focused on four different categories of particles and fibres commonly encountered in controlled environments:
Synthetic sub-visible particles (20–100 μm)
Environmental sub-visible particles and fibres (20–100 μm)
Visible particles (>100 μm)
Visible fibres (>100 μm)
Before each test, shoe soles were intentionally contaminated with a high and controlled quantity of test material. Depending on the test, this consisted either of synthetic black powder specifically selected for laboratory evaluation or environmental dust collected from an industrial facility.
The contaminated shoe soles were sampled before crossing the mat and again after only three consecutive steps. The collected particles were transferred onto microscope slides using adhesive tape lift sampling and analysed under an optical microscope, where every particle and fibre was counted and classified according to its size and type.
This methodology allowed the laboratory to accurately measure how much contamination remained on the shoe sole after walking across the mat.
What Did the Laboratory Observe?
After only three steps, the washable contamination control mat demonstrated a measurable reduction across every contamination category analysed.
Contaminant | Reduction after 3 steps |
Synthetic sub-visible particles (20–100 μm) | 58% |
Environmental sub-visible particles and fibres (20–100 μm) | 70% |
Visible particles (>100 μm) | 90% |
Visible fibres (>100 μm) | 92% |
The highest removal efficiencies were observed for visible particles and fibres, with reductions exceeding 90% after only three steps.
Sub-visible contaminants also showed significant reductions. Environmental particles and fibres between 20 and 100 μm were reduced by 70%, while synthetic particles of the same size showed a 58% reduction.
Although numerically lower, this result is fully consistent with the expected behaviour of extremely fine particles. Because of their small size and stronger adhesion characteristics, synthetic sub-visible particles represent one of the most demanding contaminant categories to remove. Demonstrating a measurable reduction after only three steps confirms the effectiveness of the contamination control process even under particularly challenging test conditions.
Overall, the results show that the mat effectively reduces contamination across a broad range of particle sizes, from large visible debris to microscopic contaminants that cannot be detected with the naked eye.
Why Were Three Steps Selected?
The study evaluated performance after three consecutive steps because this closely reflects how contamination control mats are used in practice.
When entering a controlled environment, personnel naturally walk across the mat making more than a single step. Each additional step increases the interaction between the shoe sole and the contamination control surface, progressively removing contaminants before they can be carried further into the facility.
Evaluating the mat after three steps therefore provides a realistic representation of everyday use while allowing the effectiveness of the contamination control process to be measured consistently under repeatable laboratory conditions.
More Than Just a Clean Floor
The purpose of a contamination control mat is not simply to keep floors cleaner.
Its role is to interrupt the transfer of contaminants before they reach critical areas, reducing the amount of particles and fibres carried by people and equipment as they move through a facility.
The independent laboratory study demonstrates that measurable contamination reduction begins after only a few steps, helping limit the transfer of both visible and microscopic contaminants under controlled test conditions.
When combined with appropriate cleaning procedures and facility hygiene protocols, contamination control mats become an important component of a comprehensive contamination control strategy.
Conclusion
Contamination is constantly on the move.
Every step taken inside a facility has the potential to transfer particles and fibres from one area to another. Understanding (and measuring) how effectively contamination can be reduced is therefore essential for protecting controlled environments.
The results of this study show that even after only three steps, a washable contamination control mat can significantly reduce a wide range of contaminants, including some of the smallest and most challenging particles to remove.
For facilities where contamination control is critical, preventing contaminants from moving forward is just as important as removing them once they have arrived.
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