A pressure washer jet at close range can penetrate skin without breaking it in any way that looks serious.
The entry wound is often a pinprick. There is little blood. It stings, then it aches, and the natural response is to carry on working and look at it later.
That is a high-pressure injection injury, and it is a surgical emergency. Water, and whatever chemicals and bacteria travelled with it, are now inside the tissue, spreading along tendon sheaths. Left for a few hours, it causes serious infection and can cost fingers.
Anyone in A&E needs to be told it was a high-pressure injection, because the wound looks trivial and gets triaged accordingly if you do not say so.
That is the risk nobody puts on the box, and it is the reason this page exists.
The risks that actually occur
Injection injury, as above. The one people do not know about.
Eye injury. Debris comes back off the surface at speed. Grit, paint flakes, rust and mortar fragments. This is the most frequent injury by a wide margin, and it is entirely preventable.
Slips. You are creating a wet surface and standing on it, often while pulling backwards on a hose.
Electrocution. Water, electricity and outdoor sockets. RCD protection is not optional.
Recoil and strain. A lance kicks back. Over a full day it loads wrists, shoulders and back, and a moment's inattention on a ladder turns recoil into a fall.
Chemical exposure. Detergents at working strength, plus the aerosol you are standing in.
Noise. Sustained exposure across a working day adds up.
Legionella risk. Pressure washing creates fine aerosol. Where water has stood warm in a tank or a system, that aerosol is an inhalation risk, which is why tank hygiene matters.
What to actually wear
Eye protection, always. Not sunglasses. Goggles or a face shield rated for impact. This single item prevents the most common injury.
Waterproof gloves with grip. They keep hands dry and warm, which maintains control of the lance.
Steel-toe wellingtons or safety boots with proper grip. You are working on wet surfaces all day.
Waterproof over-trousers and jacket. Comfort is a safety control here: cold, wet, tired operators make mistakes.
Hearing protection for extended use.
Respiratory protection where you are working in heavy aerosol, in confined areas, or with chemicals that require it.
Bare legs, trainers and shorts in summer are how ankle injection injuries happen.
The controls that prevent incidents
Never point it at anyone. Obvious, routinely ignored, and the reason most injection injuries happen.
Never brace your free hand near the nozzle. Two hands on the gun and the lance, both behind the jet.
Engage the trigger lock every time you stop, even for a moment.
Release the pressure before disconnecting anything. With the machine off and water disconnected, squeeze the trigger until flow stops. A hose disconnected under pressure whips.
Use an RCD on every outdoor electrical connection, and inspect leads for damage before use.
Never work off a ladder with a lance. The recoil is the problem, not the height. Use a telescopic lance from the ground, or a tower.
Check the hose before each use. Blisters, bulges and abrasions mean it goes out of service. A hose that fails at pressure is dangerous.
Cordon the area. Members of the public and colleagues walking through the spray zone are a real hazard, especially on commercial and public sites.
Look up. Overhead cables, live electrics, and windows you are about to force water past.
Your legal position at work
If pressure washing is done as part of a business, the ordinary duties apply.
A risk assessment covering the task, the site and the substances. Generic will not do; it must reflect what you actually clean and where.
COSHH assessments for the chemicals, with safety data sheets held and accessible.
Training and competence for operators, recorded. "Shown once by a colleague" is not training.
PPE provided free of charge by the employer, along with instruction on its use.
Equipment maintained in safe condition, with inspection records for hoses, guns and electrical leads.
Reporting. Certain injuries are reportable under RIDDOR, and an injection injury requiring surgery is likely to be among them.
The brief worth giving every new operator
Five minutes, once, covering the things that are not obvious:
- This can inject water under your skin without breaking it. If that happens, stop, go to A&E, and use the words "high-pressure injection injury".
- Goggles go on before the machine goes on.
- Trigger lock every time you pause.
- Never put your free hand in front of the nozzle.
- Release pressure before disconnecting anything.
- If the hose has a bulge, it does not go back on the machine.
Frequently asked questions
Can a pressure washer injure you?
Yes, seriously. The most severe risk is a high-pressure injection injury, where the jet forces water and contaminants under the skin through a wound that may look like a pinprick. It is a surgical emergency. Eye injuries from flying debris are the most common, and slips, electrocution and strain are all real risks.
What is a high-pressure injection injury?
It is when a high-pressure jet penetrates the skin and forces fluid into the tissue beneath. The entry wound often looks trivial with little bleeding, but the fluid spreads along tendon sheaths and causes rapid infection and tissue damage. Go to A&E immediately and explicitly say it was a high-pressure injection injury.
What PPE do I need for pressure washing?
Impact-rated eye protection or a face shield as the minimum, plus waterproof gloves with grip, safety footwear with good grip, waterproof over-trousers and jacket, hearing protection for extended use, and respiratory protection where aerosol or chemicals require it. Eye protection prevents the most common injury.
Can I use a pressure washer on a ladder?
No. The lance recoils when you pull the trigger, and there is no safe way to absorb that on a ladder. Use a telescopic lance from ground level, or a proper tower or platform. This is one of the more common causes of serious pressure washing falls.
Do I need a risk assessment to pressure wash at work?
Yes. Where pressure washing is done as part of a business, you need a task-specific risk assessment, COSHH assessments for the chemicals used, recorded operator training, PPE provided free of charge, and maintenance records for hoses, guns and electrical equipment.
The bottom line
The dangerous thing about a pressure washer is that it does not feel dangerous. It is loud and wet and familiar, and the worst injury it causes looks like nothing at all.
Goggles on, trigger locked, hand behind the nozzle, and everybody knows what an injection injury is before they pick one up.
Kränzle UK supplies spray guards, telescopic lances and the accessories that make the job safer as well as faster, and services machines so hoses and guns stay in safe condition. Talk to us about the kit your team is actually using.