Simulated Investigations on Surface Disinfection Work

Status:

completed

Aims:

To prepare for the planned measurement programme "Surface Disinfection in Hospitals", the inhalation exposure during surface disinfections was determined under controlled conditions in the Institute for Occupational Safety and Health (IFA) test cabin. Due to the pandemic, it was difficult or even impossible to perform exposure measurements on-site in hospitals. The findings from the experimental set-up should help with the creation of a procedure for an appropriate measurement programme. If possible, the results from the subsequent work will be used in the revised recommendation of German Accident Insurance Institutions entitled 213-709 "Surface Disinfection in Hospitals" and will also be integrated into the new German Social Accident Insurance (DGUV) Information 207-206, "Disinfection".

Activities/Methods:

Measurements were carried out with five selected disinfectants and the conventional work equipment. The main active ingredients of the disinfectants examined were formaldehyde, glutaraldehyde, ethanol, 1-propanol, 2-propanol, peroxyacetic acid and hydrogen peroxide. Overall, approx. 60 tests were carried out, each with three sample carriers and direct measuring devices. The areas that were to be disinfected ranged from 0.5 m², through 2 m² to 20 m².

The experiments at the test facility reflected the conditions of an enclosed space, as would be the case, for instance, in a hospital ward. In the test facility, the relevant surfaces were then cleaned with disinfectant wipes using the various disinfectants. Inhalation exposure was determined using both personal sampling and stationary sampling. The test involved weighing, both before and after use of the wipes.

Results:

The measurements during surface disinfection under controlled conditions showed that both the experimental set-up and the procedure are suitable for investigating inhalation exposure during surface disinfection involving various commercially available products in on-site operations. They therefore serve as the basis for defining a procedure for the planned measurement programme for on-site measurements.

To obtain the exact numerical values of the disinfected area for the quantities in relation to time, standardised details are provided in sqm/minute and multiplied by the sampling time. Sampling must be carried out during surface disinfection and other exposure-relevant activities associated with surface disinfection. If surface disinfection takes longer than 15 minutes, measurements must be taken for the entire duration of the disinfection. If surface disinfection takes less than 15 minutes, an attempt should be made to carry out further surface disinfection processes under similar boundary conditions until at least 15 minutes have been reached. Longer sampling makes it possible to reduce the limit of quantification. Sampling must always start at the beginning of disinfection and finish at the end. This must also be carried out when changing rooms.

Depending on the ingredients of the product used, three main groups of active substances can be distinguished, i.e. aldehydes, alcohols and peroxides, which – with a few exceptions – cannot be used simultaneously. So the hazardous substances to be measured should be formaldehyde, glutaraldehyde, ethanol, iso-propanol, hydrogen peroxide, peracetic acid and acetic acid.

The results will be included in the revised DGUV informative publication 213-709 "Surface Disinfection" and in the DGUV informative publication 207-206 "Disinfection", which will be written in due course.

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