Technology guide
Electrostatic disinfection explained — why a charged droplet beats a plain spray
Almost every cleaning routine already includes some form of spraying and wiping. The reason electrostatic application changes the outcome is not the chemical — it is what happens to the droplet between the nozzle and the surface. This guide explains the mechanism as Sanondaf presents it in its own technical material, and what it means in practice for staff running the machine on your own sites.
In short
Electrostatic application passes the disinfectant through a charged electrode nozzle, so every droplet leaves the gun negatively charged. Droplets are 5–50 microns — roughly 1/20th to 1/10th the width of a human hair — so the spray behaves as a dry fog that lands evenly without run-off. Surfaces are positive or neutral, so the droplets are actively pulled onto them — attraction to the surface is around 75 times greater than gravity. In Sanondaf's own indicator-fluid demonstration, an object sprayed electrostatically was coated on all faces, including the back and underside; the same object sprayed without a charge was only wetted on the side facing the gun.
6 min read ·
How does electrostatic disinfection actually work?
The spray gun carries an electrode in the nozzle. As the chemical passes through and discharges, it is given a negative charge. Negatively charged ions actively seek a host, and physical items — walls, handles, bed rails, keyboards, seat backs, chiller shelving — carry a positive or neutral charge, so they attract the chemical onto their surface.
That attraction is the whole point. Sanondaf's technical material puts the pull towards the surface at around 75 times greater than gravity. A plain spray is at the mercy of gravity and whatever direction the operator happened to point in; a charged spray is pulled onto the item and wraps around it.
Droplet size is what makes the spray a dry fog. At 5–50 microns — roughly 1/20th to 1/10th the width of a human hair — the droplets are fine enough to land evenly, avoid the run-off that wastes trigger-spray chemical, and settle into the microscopic texture of walls, grout and fabric where larger droplets simply bridge over.
What is the difference between electrostatic and non-electrostatic spraying?
Sanondaf's own demonstration puts the two side by side. Two identical objects are sprayed with an indicator fluid. With the electrostatic charge applied, the object is completely covered on all surfaces, including underneath and on the back face. Under normal spray with no static charge, only the area facing the spray is treated.
That is the honest limitation of conventional spraying and wiping: it is line-of-sight and contact-dependent. A multicentre study of 23 acute care hospitals, cited in Sanondaf's laboratory presentation, marked high-risk objects in patient isolation rooms before cleaning and found that 49% of objects and surfaces were not cleaned at all — with toilet handles, bedpan cleaners, light switches and door handles among the worst performers. Nobody is careless in those figures; the method simply relies on the operator reaching everything.
- Electrostatic: 5–50 micron charged droplets coat back faces, undersides and shadowed areas as a dry fog
- Non-electrostatic: only the face pointed at gets wetted
- Attraction to the surface is around 75 times greater than gravity
- Less reliance on operator technique, so results repeat between staff and between shifts
Where does electrostatic application earn its place over fogging?
The two are complementary rather than rivals. Whole-volume fogging treats the air and every surface in a room at once; electrostatic application is the precision tool for dense, cluttered or high-touch detail — vehicle interiors, cab controls, seating, equipment racks, servery and back-of-house furniture, cages and pens.
In practice most leased sites run both: an electrostatic machine for targeted rounds and detail work, and a fogger for the whole room. Combine the two and you have a more advanced infection control routine than many hospitals currently run.
Does it fit into cleaning that already happens?
Yes — that is the main reason clients lease rather than book callouts. Your own janitors, cleaners or housekeepers finish the standard clean, then apply electrostatically on the way out, or drop the fogger in with a small do-not-enter sign showing a safe entry time and move on to the next room. Done efficiently it adds only seconds per room.
Because a leased machine sits on your site, the round can be daily, weekly, monthly, quarterly or annual — and an outbreak response starts in about five minutes rather than waiting 6–24 hours for an operator to travel to you.
What does it cost to have one on site?
Machines are leased from £500 per month + VAT on a fixed term, with chemical supplied separately from a 100L minimum. The machines are hand-portable at around 8kg, so one unit moves room to room without a trolley or a fixed installation. Spread across a realistic 60 rooms a month, the cost per room is a fraction of a per-visit callout — and that is before you count the rooms you would never have booked an operator for.
Leasing is for approved organisations only — registered companies and institutions treating their own group sites with specifically trained staff. We do not lease to individuals.
How small is 5–50 microns?
Droplet diameter compared with the width of a human hair (about 70 microns). The fogger sits at the 5 micron end, the electrostatic spray at the 50 micron end — both smaller than a single hair, which is why they reach germs that a spray bottle simply cannot.
Dry fog droplet — SanoFog
5 microns
About 1/14th the width of a human hair. Fine enough to behave as a fog, drift on air currents and reach the whole volume of a room.
Electrostatic droplet — SanoStatic
50 microns
Still well under a hair's width. Charged, so it is pulled onto surfaces and wraps around edges — even coverage, no run-off.
Human hair
70 microns
The reference point: roughly 70 microns across.
Trigger spray bottle droplet
100+ microns
Typically 100 microns and above — larger than a hair, so droplets hit, run and drip instead of settling into surface texture.
Bars are scaled against a 70 micron hair; the spray bottle bar is capped because its droplets are wider than the scale. Both Sanondaf outputs are dry — nothing is left wet to dry off.
Frequently asked
- Is electrostatic spraying just marketing?
- No. The mechanism is measurable and Sanondaf demonstrates it with indicator fluid: with the charge applied, an object is coated on all faces including the back and underside; without it, only the sprayed face is wetted. The droplets are 5–50 microns — a dry fog — and the stated attraction to the surface is around 75 times greater than gravity.
- Does it replace normal cleaning?
- No. It is applied after the standard clean. Soil and organic matter should be removed first; disinfection then handles what cleaning cannot reach or verify.
- Is it safe around electronics and equipment?
- The hydrogen peroxide based chemistry breaks down to water and oxygen and leaves no residue. In published laboratory work cited in Sanondaf's material, no surface or material damage was noted after dry mist hydrogen peroxide exposure in a BSL3 laboratory containing safety cabinets, incubators, freezers and computing equipment.
- Can our own staff be trained to use it?
- Yes — that is the model. Approved organisations are trained on the equipment and chemistry, and can call our office for a supervised first treatment or a hybrid attendance at a reduced rate if an event feels beyond the routine.
Sources: material published by Sanondaf UK at sanondaf.co.uk (news, research and case studies) and the technical and commercial documentation held by the Shropshire & West Midlands office. Figures are indicative and confirmed at survey. Efficacy is stated as up to 99.9999% reduction.