What is the difference between cleaning, disinfection and sterilisation?

They are three distinct levels. Cleaning removes visible soil and most of the microbial load with water and detergent, and it is the precondition for everything else. Disinfection reduces pathogenic microorganisms on surfaces with chemicals, but does not necessarily kill all spores. Sterilisation eliminates every microbial form, spores included, and applies to instruments through an autoclave, not to environments. A clinic needs all three, but for spaces and surfaces the reference level is disinfection, always preceded by effective cleaning.

Why is contact time so important?

Because a disinfectant does not act the instant it touches a surface: it needs to stay in contact, wet, for the time stated by the manufacturer to kill the target microorganisms. If you wipe it dry at once, or it evaporates first, you get a partial disinfection that gives false confidence. In practice this means applying enough product to keep the surface wet for the full stated time, reapplying if needed, and not treating large areas with products that evaporate too quickly.

Do I need a different product for every area of the clinic?

Not necessarily one per area, but not the same everywhere either. A sensible approach is a daily use disinfectant for low and medium risk areas and a broad spectrum one for wards, isolation and extraordinary decontaminations. The mistake to avoid is the opposite extreme: using the most aggressive product everywhere burns budget, damages surfaces, exposes staff and can paradoxically encourage resistance. The choice is made on the area's risk, not on habit.

How often should the protocol be updated?

The protocol should be reviewed whenever something substantial changes: a new disinfectant, a new procedure, a refurbishment of the spaces, or the appearance of a healthcare associated infection. Beyond these occasions, a scheduled review at least once a year keeps the document matched to actual practice and reinstates what has slackened over time. Every review should come with a short team training, otherwise the updated document stays a dead letter.

Clinic operations60 minLevel: AdvancedUpdated on August 20, 2026

Setting up an environmental cleaning and disinfection protocol for the clinic

A written protocol to clean and disinfect clinic environments: areas by risk level, product choice, contact times, procedures and a signed log everyone can follow.

Audience: Veterinarians
Species: All species
Scope: Valid everywhere, Italy, European Union

What you need before you start

La pianta della struttura con le aree suddivise per livello di rischio
Le schede tecniche e di sicurezza dei disinfettanti già in uso
Un referente formato che possa aggiornare il protocollo e verificarne l'applicazione
Un registro cartaceo o digitale per firmare pulizie ordinarie e straordinarie

In a veterinary practice, surfaces are not all the same and should not be treated the same way. A waiting room floor, an examination table, an infectious ward cage and the surgical prep counter carry different risks and call for different products, frequencies and procedures. An environmental cleaning and disinfection protocol is not a list of good intentions pinned to a board: it is a working document that tells whoever cleans what to use, where, when, with what contact time and with what verifying signature. This guide separates cleaning from disinfection, organises spaces by risk level, helps you choose disinfectants while respecting contact times, and helps you put in writing a procedure that holds even when the practice is under pressure. It does not cover instrument sterilisation, which follows a path of its own.

Dividing spaces by risk level

The first step is not choosing a product, it is mapping the spaces. Each area should be classified by the likelihood of contamination and the vulnerability of the patients that pass through it. Frequencies and products flow from this map: applying the same protocol everywhere means over disinfecting where it is not needed and under disinfecting where it counts.

Low risk areas: reception, waiting room, offices. Visible dirt and traffic, but no vulnerable patients. Frequent cleaning, targeted disinfection of touch points.
Medium risk areas: consulting rooms, treatment rooms, through corridors. Direct contact with different patients all day. Surface disinfection between patients.
High risk areas: wards, surgery, prep, infectious isolation. Vulnerable or potentially contagious patients. Strict protocols, separated routes, broad spectrum products.
High frequency touch points: handles, keyboards, phones, pens, thermometers, the scale. Small, forgotten and responsible for much of the cross transmission.

Choosing disinfectants and respecting contact times

Disinfection only works after effective cleaning: organic soil, blood, pus, faeces, inactivates many disinfectants before they can act. The rule is always the same, clean and rinse first, then disinfect. And a disinfectant does not work the instant it touches a surface: it needs to stay wet for its contact time, the one stated by the manufacturer, which is often several minutes.

Indicative features of the main disinfectant families. The binding reference remains the technical sheet of the product in use and its dilutions.
Family	Strengths	Limits	Typical use
Quaternary ammoniums	Good on surfaces, low corrosion, well tolerated	Inactivated by organic soil, limited spectrum on some viruses	Consulting rooms, medium risk surfaces
Accelerated peroxides	Broad spectrum, short contact times, low residue	Higher cost, need care with some materials	Wards, frequently touched surfaces
Active chlorine	Broad spectrum, effective even on spores at high concentration	Corrosive, irritant, inactivates fast, must be diluted fresh	Infectious isolation, decontaminations
Alcohol 70 per cent	Fast on small points, evaporates without residue	Flammable, ineffective on spores, evaporates before the useful time on large areas	Touch points, small surfaces

The daily cleaning procedure

A written procedure turns an act that depends on the person into a repeatable standard. It must be short enough to hang near the area and precise enough to leave no room for interpretation. This is the basic scheme for a medium risk environment, to be adapted for more sensitive areas.

Put on personal protection
Gloves suited to the product and, where required, eye and respiratory protection. The staff who clean are the first exposed to concentrated disinfectants and should be protected like those handling drugs.
Remove visible soil and waste
Clear organic material, swabs, bedding and waste into the correct containers. Disinfecting over soil is time wasted, because the product is used up on the residue instead of on the microorganisms.
Clean with water and detergent
Wash the surface to remove grease and the organic film, then rinse. This is the phase that knocks down most of the load: disinfection completes it, it does not replace it.
Apply the disinfectant at the correct dilution
Spread it evenly and keep the surface wet for the full stated contact time. If it dries sooner, reapply: a halved contact time is a halved disinfection.
Respect the time, then rinse if required
Wait the stated minutes without moving on. Some products need rinsing, especially where animals lick surfaces or where irritant residues remain.
Tidy equipment and cloths
Cloths and mops do not move from a dirty area to a clean one: use different colours or codes per zone and wash or discard them per protocol. One contaminated cloth undoes all the work done.
Sign the log
Record area, time, product and operator. The signature is not bureaucracy: it lets you reconstruct what was done when a problem arises and confirm that no area was skipped.

Deep cleaning after an infectious case

After a patient with a suspected or confirmed transmissible disease passes through, routine is not enough. A dedicated decontamination is needed, with broad spectrum products and attention to the details usually overlooked, because that is exactly where transmission restarts.

Isolate the area and take it out of use until decontamination is complete and verified.
Remove and treat as contaminated any bedding, drapes, bowls and single use materials, disposing of them per the risk category.
Clean every surface thoroughly before disinfecting, including the low parts of tables and cages where soil accumulates.
Apply a broad spectrum disinfectant active against the suspected agent, respecting the dilution and the longest stated contact time.
Do not forget the hidden points: trolley wheels, handles, switches, the floor under cages, fans.
Let it dry, return the area to service only after verification, and log the intervention as extraordinary, noting the reason.

Recording, verifying and training the staff

A protocol only truly exists if it is applied, verified and known by those who work with it. The three go together: without a log you do not know what was done, without verification the log becomes an automatic signature, without training the most precise procedure stays unapplied.

A log per area with time, product and signature, routine and extraordinary kept distinct, readable at a glance.
Periodic spot checks, including visual ones, to confirm surfaces are genuinely clean and contact times are respected.
Dilutions and contact times written next to each product, not left to the memory of whoever mixed the solution.
A protocol review whenever a product or procedure changes, or when a healthcare associated infection emerges.
Training for every new team member on arrival and periodic refreshers for everyone, because habits slacken over time.

Frequently asked questions

What is the difference between cleaning, disinfection and sterilisation?: They are three distinct levels. Cleaning removes visible soil and most of the microbial load with water and detergent, and it is the precondition for everything else. Disinfection reduces pathogenic microorganisms on surfaces with chemicals, but does not necessarily kill all spores. Sterilisation eliminates every microbial form, spores included, and applies to instruments through an autoclave, not to environments. A clinic needs all three, but for spaces and surfaces the reference level is disinfection, always preceded by effective cleaning.
Why is contact time so important?: Because a disinfectant does not act the instant it touches a surface: it needs to stay in contact, wet, for the time stated by the manufacturer to kill the target microorganisms. If you wipe it dry at once, or it evaporates first, you get a partial disinfection that gives false confidence. In practice this means applying enough product to keep the surface wet for the full stated time, reapplying if needed, and not treating large areas with products that evaporate too quickly.
Do I need a different product for every area of the clinic?: Not necessarily one per area, but not the same everywhere either. A sensible approach is a daily use disinfectant for low and medium risk areas and a broad spectrum one for wards, isolation and extraordinary decontaminations. The mistake to avoid is the opposite extreme: using the most aggressive product everywhere burns budget, damages surfaces, exposes staff and can paradoxically encourage resistance. The choice is made on the area's risk, not on habit.
How often should the protocol be updated?: The protocol should be reviewed whenever something substantial changes: a new disinfectant, a new procedure, a refurbishment of the spaces, or the appearance of a healthcare associated infection. Beyond these occasions, a scheduled review at least once a year keeps the document matched to actual practice and reinstates what has slackened over time. Every review should come with a short team training, otherwise the updated document stays a dead letter.

What to do next

Start from the map of environments by risk level, then choose disinfectants on that risk, always keeping the sequence clean, rinse, disinfect for the full contact time. Put in writing the daily procedure and the deep clean after infectious cases, do not neglect high frequency touch points and the dirty and clean routes. Log every intervention with a signature, spot check the results and train the whole team, updating the protocol at every change.