Register
 (photo: Karolina Grabowska)
12.06.2020, 14:43

Why You Really Need to Know Your Disinfectants

Cleaning & Waste Management, The Indoor Environment

Steve Teasdale, InnuScience co-Founder and Vice-President of Scientific Affairs, explains why recognising differences between bactericides, virucides and fungicides is essential for COVID-Security.


At a time when we're being bombarded with advertising, guidance, and often conflicting information on containing the spread of Covid-19, taking the time to consider what public health advice to clean, clean properly, and clean often actually means, can yield dividends.

 

For the success of any disinfection operation is determined as much by science as by the skills, and experience of cleaning operatives which requires an awareness of the different terms used by chemical manufacturers - and even greater awareness of a market tendency for these terms to be applied broadly with little regard to their true meaning.

 

Bactericides

Bactericides are substances that kill bacteria - microscopic, single-cell organisms with a simple internal structure containing 'free-floating' DNA (i.e., no nucleus; ‘prokaryotic’). Most bacterial cells are surrounded by an outer cell wall and an inner cell membrane, whilst some have no cell wall, and some have a third protective outer layer called a capsule.

 

A  gram  stain  is  used  to  identify  and  classify  bacteria  based  on their cell wall composition; a gram stain is a test that is able to stain ‘Gram-positive bacteria’, as they do not have an outer cell wall, whilst ‘Gram-negative bacteria’ do not pick up the stain, due to the presence of an outer cell wall. Further classification of bacteria is based on their shape; round bacteria are called ‘cocci’ (singular ‘coccus’), cylindrical, capsule shaped bacteria are called ‘bacilli’ (singular ‘bacillus’), and spiral bacteria are called ‘spirilla’ (singular: ‘spirillum’).

 

Bactericides kill bacteria in a variety of ways, including protein denaturation (breakdown), penetration of the cell wall, loss of intracellular (within the cell) contents, inhibition of protein synthesis (building of proteins), decreased oxygen uptake, DNA fragmentation, depression of DNA synthesis, depression of cell wall synthesis, decreased bacterial cell ‘energy’ production, or the production of destructive ‘free radicals’ - highly reactive atoms that can attack and damage membrane lipids, DNA or other essential cell components. Bacterial spores (highly resistant, dormant structures formed to ensure the survival of bacteria through adverse environmental conditions) cannot be destroyed by all chemical disinfectants and must be killed by sterilization (typically at high temperatures and under high pressures).

 

Virucides

Virucides are substances that kill viruses. Viruses consist of three main ‘building blocks’: (1) Ribonucleic acid (RNA), the viral genetic material similar to DNA; (2) proteins; and (3) lipids, the outer coating of the virus that protects the genetic material and aids with viral spread and cellular invasion. These three components spontaneously self-assemble to form a complete virus, with weak ‘non-covalent’ bonds between the proteins, RNA and lipids.

 

Virucides can kill viruses in multiple ways, including protein denaturation, loss of intracellular contents,
inhibition of protein synthesis, decreased oxygen uptake, DNA fragmentation, alteration of RNA synthesis,
the production of destructive free radicals and by altering the integrity of the viral outer lipid membrane.
Virucides in particular are effective at blocking RNA synthesis, as this is needed for viral multiplication.

  

Fungicides

Fungicides are substances that kill fungi. Fungi are complex, ‘eukaryotic’ (i.e., DNA is contained within a membrane structure called a nucleus) cells, similar to animal cells, possessing an inner cell membrane and an outer cell wall. Fungi cell membranes contain a specific type of cholesterol, called ‘ergosterol’, which helps to maintain cell membrane fluidity and integrity.

 

Fungicides can kill fungi in multiple ways, including protein denaturation, decreased oxygen uptake, depressed DNA synthesis, inhibition or reduction of  protein  synthesis,  DNA  fragmentation,  alteration  of RNA synthesis, and the production of destructive free radicals. Other fungicides act to inhibit the synthesis of, or directly interact with, ergosterol in the fungi cell membrane. 

 

Notwithstanding all of the above, it's still worth remembering throughout the coronavirus pandemic that there's a simple message to follow.

 

Wash your hands regularly with soap and water all the way up to your wrists and for a minimum 20 seconds, wash down all surfaces and equipment regularly with an effective detergent or soap, and focus disinfection actions on high-touch critical areas by implementing a regular programme of targeted hygiene within your facility.

 

 

 

 

Article rating:

vote data

Leave a reply

Simon Lane, Director, Leisure at Serco. (photo: Serco Group)
News Editor  - 07.07.2021

Serco Announces Major New Appointment

Serco has announced the appointment of Simon Lane in the newly created position of Director, Leisure, leading all contracts within the group's leisure portfolio.

Pictured: Jeff Dewing, Cloudfm Chief Executive Officer. (photo: Cloudfm Group)
News Editor  - 28.06.2021

A Leader in IoT Predictive Maintenance

Gartner has named Cloudfm a global leader in IoT enabled predictive maintenance in a new report on the benefits of the technology and its role in digital transformation across different industries.

 (photo: Rodolfo Clix)
Valpy Fitzgerald  - 16.07.2021

Beware of Power Purchase Agreements

Valpy Fitzgerald explains why hidden charges are derailing promises of higher purchase prices for businesses supplying energy into the UK's National Grid under power purchase agreements (PPAs).

 (photo: Cottonbro)
Andrew Barry  - 01.07.2021

Don't Sweat the Small Stuff

OUTCO managing director Andy Barry explains why packaged outdoor FM services makes sense for estates managers.

 (photo: Compass Group UK & Ireland)
News Editor  - 18.12.2020

Providing 20,000 Meals to Those in Need

The Wimbledon Foundation has extended its support for organisations addressing food poverty at Christmas and beyond as part of its response to COVID-19.

 (photo: CPD Global)
News Editor  - 18.12.2020

Ecolab Named to CDP A Lists

The Carbon Disclosure Project (CDP) has added Ecolab to its A List for Climate, as well as Water Security.

 (photo: Bodet SA)
News Editor  - 17.12.2020

Enhancing Home Worker Visibility

Bodet have extended the coverage of the Kelio time and attendance software solution to staff working at home.