The purpose of this trial was to validate cleaning indoor nicotine and cannabis contamination which is described as a ‘Red’ result by the Swab First National laboratory.



Initial sample collection and analysis


A trained Swab First authorised sampler collected a sample from a vacant and uncleaned residential rental property in Adelaide, South Australia. Numerous surfaces within the property were sampled using the Swab First sampling protocol. The property did not smell of tobacco smoke or have visual evidence of contamination to indicate smoking had occurred inside the property.

The sample was analysed at the Swab First National laboratory and a 'Red' result was obtained for both nicotine and cannabis.


Extensive distribution sampling and analysis


Following the initial sample, an extensive distribution sampling exercise was performed by Swab First. A total of 35 samples were collected from various interior surfaces. Every wall inside the home was sampled as well as benches and frequently touched surfaces such as light switches and door knobs.

The samples were analysed at the Swab First National laboratory and 24 samples (69%) were positive for nicotine and 1 sample (3%) was positive for cannabis. The distribution of contamination inside the property is shown in Figure 1. Nicotine contamination was widespread throughout the property whereas the cannabis contamination was isolated to the kitchen bench.

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Figure 1 – Indoor contamination distribution

Property Cleaning


The following cleaning activities were performed inside the property:

All the surfaces were washed using an alkaline detergent solution

All the carpets were steam cleaned

An ‘end of lease clean’ including all the windows

The total cleaning cost was less than $1,500


Cleaning Validation


Following the property clean, the extensive distribution sampling exercise was repeated by Swab First. All 35 samples returned a ‘Green’ result for all of the seven substances on the Swab First analytical profile, including nicotine and cannabis. This indicated no substance was detected by the Swab First national laboratory.

The Swab First authorised sample collector also performed a re-test at the same locations after the clean and a ‘Green’ result was also achieved for all seven substances.


Conclusion


The cleaning activities performed in this trial effectively removed indoor nicotine and cannabis contamination (described as a ‘Red’ result by the Swab First National laboratory). There was also a notable improvement to the appearance of the property following the clean. The cleaning activities were cost-effective and consistent with the cleanliness expectations placed on outgoing tenants.