Alert: Using high-pressure water-jetting guns
Using a high-pressure water-jetting gun without a safe way to control the flow of water can put you and others at risk of injury or death. Read this alert to learn more about working safely with this equipment.
Issued on May 2, 2018.
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Workers who work with high-pressure water-jetting guns, or other people nearby, may be injured or killed if struck by the high-pressure water stream or any material that’s released by a high-pressure water stream.
High-pressure water-jetting guns are used in the construction industry, by drain-cleaning services, water-blasting services, concrete-cutting services and other cleaning services.
Workers use them to:
- clean surfaces
- remove material from catch basins
- dig holes and excavations by removing soil
Equipment such as pumps and motors pressurize water that is then sprayed toward surfaces or material.
The stream of water is often under enough pressure that it can cut flesh, damage eyes or cause other serious injury to people.
Workers have been hurt by being hit with a high-pressure stream of water; in at least one case, a worker died from the injury.
This may happen if the worker using the high-pressure water-jetting gun does not have a way to shut off the flow of high-pressure water immediately with an operator-controlled triggering valve or other device.
Actions for employers
Under section 25 of the Occupational Health and Safety Act employers have various duties, such as ensuring that:
- equipment, including high-pressure water-jet guns, is maintained in good condition
- measures and procedures prescribed in regulations are followed
- equipment is used as prescribed by regulations
- workers are provided with information, instruction and supervision to protect their health and safety
Operator-controlled triggering valve
Employers are required by law to take every precaution reasonable in the circumstances for the protection of a worker. This includes precautions to protect a worker from being struck by the flow of water when using a high-pressure water-jetting gun.
One reasonable way to protect workers is to have an operator-controlled triggering device in place.
An operator-controlled triggering valve is a safety feature designed to minimize the risk of injuries to the operator and other workers.
The operator must continuously hold the triggering valve in the ’working’ or ‘on’ position so water flows through the nozzle. In the event of an accidental loss of control of the jetting gun, the triggering valve automatically returns to the neutral position, stopping the flow of water.
- An operator-controlled triggering device can be in the form of a hand-operated valve or foot-activated valve with a protective frame and/or a shroud to prevent accidentally turning on the water.
- There may be other devices that will automatically shut off the flow of water in the event of an accidental loss of control of the water-jetting gun. Use of these may also provide reasonable levels of protection.
Equipment use and maintenance
Section 93 of Regulation 213/91– Construction Projects requires that vehicles, machines, tools and equipment
- be maintained in a condition that does not endanger a worker
- be used according to manufacturer’s instructions
This means that employers on a construction project:
- must not allow equipment to be used if it is not working properly
- must ensure that the manufacturer’s instructions for the safe operation of high-pressure water-jetting equipment are followed
Employers may also check ASTM Standard E1575-12, Standard Practice for Water Cleaning and Cutting as a guideline for accepted practices in high-pressure water-jetting.
Personal protective equipment
Under section 81 of Regulation 851– Industrial Establishments and section 24 of Regulation 213/91– Construction Projects, workers must wear eye protection when there is a risk of eye injury. This includes a hazard of eye injury when using a high-pressure water-jetting gun, or if another worker nearby is also at risk of eye injury.
Other protective equipment such as gloves or protective clothing may also be required if there is a hazard of injury to workers.
If the manufacturer’s instructions include information on appropriate personal protective equipment, these instructions should be followed. This applies to work at both construction projects and industrial establishments.
If you need more information about safety requirements, please contact the Ministry of Labour Health & Safety Contact Centre at
This resource does not replace the Occupational Health and Safety Act (OHSA) and its regulations, and should not be used as or considered legal advice. Health and safety inspectors apply the law based on the facts in the workplace.