The droplets are given an electrical charge as they leave the nozzle, so they repel each other into an even spread and are attracted to earthed surfaces.

Mutual repulsion between like-charged droplets prevents them from merging, which produces a more uniform coating than an uncharged spray of the same volume.

Attraction to earthed objects is what gives the wrap-around effect. Droplets curve toward the nearer surface and deposit on sides and undersides that were never in the line of the nozzle.

The effect depends on the target being earthed or at least electrically different from the charged droplets. On well-insulated or already-coated surfaces the benefit falls away as charge accumulates.

It is a delivery method, not a disinfection method. The chemistry, the concentration and the contact time still determine whether anything is disinfected.

No - the solution must be electrically conductive enough to take a charge and chemically compatible with the equipment.

Conductivity is the requirement most often missed. A solution that will not hold a charge sprays as an ordinary fine mist, so the operator gets neither the even coverage nor the wrap-around and has no way of telling.

Viscosity and surface tension affect atomisation. A product formulated for a trigger bottle may produce droplets too large or too variable for the equipment.

Corrosion matters because the solution passes through the pump, tubing, nozzle and the charging electrode. Chlorine-based products are the usual culprits and will damage equipment not designed for them.

Sprayer manufacturers publish lists of compatible solutions. Using an unlisted product generally voids the warranty and frequently degrades performance in ways that are invisible.

No - it replaces spraying, not cleaning. Soil still has to be removed mechanically before any disinfectant is applied.

Disinfectants are inactivated by organic soil and cannot reach organisms beneath a film of residue. Spraying a dirty surface, however evenly, achieves very little.

The realistic role is to disinfect surfaces that have been cleaned, and to reach complex or large areas quickly - seating, gym equipment, vehicle interiors, classrooms, warehouses.

For high-touch points where the risk is greatest, wiping with mechanical action remains more reliable, because it both removes and kills.

Most well-designed protocols use both: routine wiping of touch points, with electrostatic application for whole-area treatment where coverage by hand would be impractical.

Often less time than the product's contact time requires - which is the main technical weakness of the method and needs checking.

Electrostatic sprayers deliver fine droplets in a thin coating. A thin coating dries faster than a surface wetted by trigger spray, and if it dries before the contact time elapses the claimed efficacy is not achieved.

The check is direct: treat a surface, and observe whether it is still visibly wet at the end of the stated period. If not, either the application rate must increase or a product with a shorter contact time is needed.

Room temperature, airflow and humidity all shorten the wet time considerably, so a process validated in one environment may fail in another.

Some products are specifically formulated with a short contact time for this application, which is a more reliable answer than trying to apply more solution.

Respiratory protection and an unoccupied area, because the method deliberately produces a fine airborne mist.

Fine droplets remain airborne for a considerable time and are readily inhaled. That is an inherent consequence of the technique rather than a fault, and it is why treatment is normally carried out in unoccupied spaces.

The operator needs respiratory protection appropriate to the product, plus eye protection and gloves. The safety data sheet specifies what.

A re-entry time should be set and enforced - long enough for the aerosol to settle and the area to ventilate. Manufacturers typically state one.

Electronics, food, food packaging and open materials must be removed or covered before treatment.

Electrical safety matters too: spraying conductive solution around live equipment and outlets requires the area to be prepared, and the sprayer itself is a charged device.

Large areas with complex shapes that have already been cleaned - transport interiors, gyms, classrooms, waiting areas, warehousing.

The advantage is coverage per unit of time on surfaces that would take a long while to treat by hand: rows of seating, exercise equipment, racking, vehicle interiors.

Wrap-around genuinely helps on complex geometry, where the sides and undersides of items would otherwise be missed.

It is poorly suited to heavily soiled environments, to surfaces that must not get wet, and to situations where a specific high-touch item needs reliable treatment - a wipe is better for that.

Cost is a factor in both directions: equipment and compatible solutions cost more, while labour per square metre falls substantially on the right kind of area.

It is not a substitute for a cleaning programme, and specifying it as one is the most common mistake made with the technology.

Flush after every use, keep the nozzle and electrode clean, and never leave solution standing in the tank or lines.

Residue dries in the nozzle and on the charging electrode, and a fouled electrode stops imparting charge - so the sprayer keeps working while quietly ceasing to be electrostatic.

Flushing with clean water after each use is the single most important maintenance task, and it is more important with chlorine or acidic solutions.

Filters and nozzles are consumables and block progressively, which shows as changed droplet size and reduced output.

Battery packs on cordless units need the usual care - not stored flat, not charged hot.

Periodically verify the charge is being applied. Some units have an indicator; otherwise, the test is whether the spray shows the characteristic attraction to a surface rather than simply falling.