Cleaning equipment

Robertson, A. et al. 2019. Combining detergent/disinfectant with microfibre material provides a better control of microbial contaminants on surfaces than the use of water alone.


  • To investigate the impact of using
    • water vs quaternary ammonium compounds (QAC)-based detergent/disinfectant
    • or water vs sporicidal products
    • in combination with a microfibre material.
  • Measurements made without and with organic load
  • The ASTM2967-15 standard test method was used to measure wipe products’ efficacy: bacteria/spores removal from, and transfer between surfaces.


  • Staphylococcus aureus and Acinetobacter baumannii and spores of Clostridium difficile were used
  • Materials: stainless steel and PVC with PUR-coating
  • A 10-s wiping time with 300 g weight was used with the detergent/disinfectant and sporicidal products as it reflects the conditions of use in practice.
  • For the transfer experiment, the used wipe was used to wipe a clean surface (10 s, 300 g) immediately after the initial wiping.


  • There was a significant difference in the number of bacteria removed from surfaces following wiping between the use of water alone and the detergent/disinfectant product, regardless of the type of surface.
  • Wiping with water
    • Reduced bacterial counts mostly by 1-2 log10, but
    • bacterial transfer from the microfibre to a different surface following wiping was significant (3-4 log10 bacterial transfer).
  • Wiping with detergent/disinfectant
    • Reduced bacterial counts by 3-5 log10.
    • Significantly prevented the transfer of bacteria to clean surface.
  • Wiping with sporicidal product
    • Significantly reduced the concentration of C. difficile spores comparing to the use of water regardless of the type of surfaces and organic load.
    • Prevented the transfer of C. difficile spores between surfaces, regardless of the type of surfaces or level of organic load.
    • The use of water was associated with significant spore transfer 15 min post-wiping or 24 h after wiping.
  • The level of organic load did not affect the efficacy of the test product and material performance.


  • The use of water alone with a microfibre cloth is less effective and should not replace the use of biocidal products.

Smith, D.L. et al. 2011. Assessing the efficacy of different microfibre cloths at removing surface micro-organisms associated with healthcare-associated infection.


  • To investigate the ability of 10 different microfibre cloths (one disposable, 9 re-usable)
    • to remove microbial contamination (methicillin resistant Staphylococcus aureus (MRSA), Clostridium difficile (in spore form) and Escherichia coli
    • from three surfaces commonly found in hospital settings (stainless steel, furniture laminate and ceramic tile),
    • under controlled laboratory conditions.
  • To study the effect of laundry to cloths.
  • To study the effect of repeat cloth use.


  • One hour prior to testing, cloths were placed in separate plastic bags and dampened with volumes (as per manufacturer’s instructions) of sterile distilled water.
  • Surface cleaning trials were conducted using a custom-made automated cleaning rig.


  • The mean reduction of micro-organisms was 2.21 log10.
  • No significant differences between microfibre cloths /except disposable cloth, was the worst).
  • The performance of all cloths decreased with repeated use on a succession of contaminated surfaces.
  • After repeated washing, re-usable cloth performance improved at 75 washes, and reduced after 150 washes, although, in most instances, performance after 150 washes was better than at first wash.

Terpstra, P. M. J. et al. 2015. Efficiency of multi-use micro fibre flat mops versus disposable micro fibre
flat mops.


  • To test and compare the effectiveness aspects of disposable micro fibre flat mops to multi-use micro fibre flat mops in a controlled laboratory research study, using practical simulation.
  • The effectiveness aspects compared: the cleaning action, cleaning exertion, dirt-binding capacity and hygienic effectiveness.


  • 4 multi-use and 4 disposable flat mops dampened with a detergent solution.
  • Floor materials: linoleum, vinyl and stone tiles.
  • A cleaning robot was used, so that the cleaning pressure, the length of the wiping movement and the wiping speed could be adjusted.
  • Three types of test dirt: chocolate milk, sebaceous matter and street sweepings, and for hygiene tests a culture that contained a mixture of micro-organisms.
  • The cleaning pressure value was determined for normal/light cleaning, normal/intensive cleaning and thorough/localised cleaning.
  • The number of wiping movements required to remove a stain was recorded as a measure of cleaning speed.
  • The result of a visual assessment of the dry, cleaned surface was a measure for cleanliness.


  • On average multi-use micro fibre mop was better to remove all the test dirt.
  • There were, however, differences within mops.
  • The frictional resistance of both the multi-use and the disposable flat mops differed significantly within their respective groups. The highest cleaning resistances were measured with the disposable flat mops and the lowest with the multi-use.
  • With one exception, all in all the flat mops removed a stain with a substantial amount of the germs present within it. The log reduction was from 2.0 to 2.7 (99.0 to 99.8 % of the present germs).

Terpstra, P. M. J. 2021. Scrubber drier hygiene.


  • During the use, can scrubber driers spread through the air microorganisms that have been removed from the floor together with dirt.

Methods and results

Two series of experiments

  • Was the liquid in the wastewater tank contaminated with microorganisms after use in a practical situation.
    • Substantial numbers of microorganisms were found in all wastewater tanks of the scrubbing machines that were investigated. The average germ count measured per hospital varies from 4.4 to 7.1 log TPC/ml.
  • Were the microorganisms in the vacuumed cleaning fluid spread into the ambient air during scrubbing.
    • The result of the study implies that there is no indication that scrubbing and drying with a medium-sized conventional single-disc scrubber drier
    1) spreads microorganisms removed from the floor into the ambient air, and
    2) that users/residents of an area in which scrubbing takes place and/or the person operating the scrubber drier are exposed to a hygiene risk as a result.

Terpstra, P. M. J. & van Kessel, I. 2018. Hygiene of Refillable Spray Bottles.
Terpstra, P. M. J. et al. Hygiene of refillable spray bottles II.

Objectives, study I

  • To explore if spray bottles in the institutional cleaning sector are microbially contaminated, and if so, pose a hygiene risk.
  • If a microbial contamination does exist, to determine whether the organisms are freely found in the residual liquid in the spray bottles (free germs) or also in any biofilm (bound germs).
  • To determine whether an existing contamination can be eliminated with a single hygienic treatment using a disinfectant (active chlorine).

Results, study I

  • The liquid in refillable spray bottles used in institutional practice may be microbially contaminated.
  • Germs were found in 33 of the 55 spray bottles examined.
  • The degree of contamination ranged from 3.0 log CFU up to 9.0 log CFU per spray bottle.
  • The spray bottles contained both free germs and bound germs.
  • The numbers of bound germs were in the same order of magnitude as the numbers of free (unbound) germs.
  • A single hygienic treatment of contaminated spray bottles does not result in uncontaminated spray bottles.

Objectives, study II

  • To investigate to what extent the hygiene of spray bottles in institutional cleaning practice improves with the application of a daily hygienic treatment in compliance with the guidelines of the Dutch Working Party on Infection Prevention (WIP) and the Dutch National Institute for Public Health and the Environment (RIVM).

Methods and results

Laboratory study

  • Spray bottles were exposed to an infected cleaning agent for 6 hours every day for a period of 14 and 28 days.
  • Half of the spray bottles in the study were treated hygienically (daily) after exposure in accordance with the WIP/RIVM guidelines; the other half received no hygienic treatment (only emptying).
  • A neutral daily cleaner, a neutral interior cleaner and an alkaline sanitary cleaner were used as cleaning agents.
    • The spray bottles that were exposed to contaminated sanitary cleaner and treated hygienically remained uncontaminated.
    • In all other spray bottles, contamination was found after 14 and 28 days.

Field study

  • Unused new spray bottles were issued at 7 Dutch healthcare institutions.
  • The cleaning staff were requested to use the spray bottles in their normal daily routine.
  • The spray bottles had to be treated hygienically at the end of every working day in compliance with the hygiene guidelines of the WIP/RIVM.
  • After a period varying from 11 to 52 days, the spray bottles were collected for hygienic examination.
    • In 3 of the 7 institutions, no contamination was found in any of the spray bottles used.
    • In 4 institutions contamination to a greater or lesser degree was found.
    • The infection rate for the contaminated bottles ranged from 3.2 to 7.0 log CFU.
    • Comparison of this result with previous research provides indications that the average and maximum degree of contamination is reduced by a hygienic treatment in compliance with the WIP and RIVM.