What regulations apply to industrial tank cleaning?

Industrial tank cleaning is governed by a combination of national safety legislation, international standards, confined space entry rules, hazardous material handling requirements, and equipment certification frameworks. Any operation involving entry into or mechanical cleaning of a storage tank must comply with regulations covering worker safety, environmental protection, and equipment suitability. The specific rules that apply depend on your country, industry sector, and the substances previously stored in the tank. This article breaks down the key regulatory questions every maintenance engineer and field technician should be able to answer before starting a tank cleaning job.

Which regulatory bodies set the rules for industrial tank cleaning?

Industrial tank cleaning is regulated by a combination of national occupational safety authorities, industry-specific standards bodies, and professional water jetting associations. In the Netherlands, SIR (Stichting Industriële Reiniging) sets guidelines for industrial cleaning operations. Across Europe, the EWJI (European WaterJet Industry) establishes best practices, while the WJA (WaterJet Association) covers the UK, the WJTA (WaterJet Technology Association) governs standards in the USA, and the DIRV provides the framework in Germany.

Beyond these professional associations, tank cleaning operations must also align with broader regulatory frameworks. In the European Union, the Machinery Directive and the ATEX Directive apply to equipment used in potentially explosive atmospheres. Environmental agencies such as the Dutch RIVM or the European Environment Agency influence how waste streams and chemical residues are handled during and after cleaning. In the petrochemical and energy sectors, additional standards from bodies such as the API (American Petroleum Institute) and ISO are commonly referenced for storage tank maintenance protocols.

Because tank cleaning spans multiple disciplines, including confined space entry, hazardous material handling, and high-pressure equipment operation, no single body covers everything. Compliance typically means satisfying the requirements of several overlapping authorities simultaneously.

What are the confined space entry requirements for tank cleaning?

Confined space entry for tank cleaning requires a formal permit-to-work system, a written risk assessment, continuous atmospheric monitoring, a trained standby person stationed outside the tank, and an emergency rescue plan in place before any worker enters. These requirements are non-negotiable under most national occupational health and safety legislation.

A storage tank qualifies as a confined space because it has limited means of entry and exit, is not designed for continuous occupancy, and may contain hazardous atmospheres including oxygen-deficient air, toxic gases, or flammable vapours from residual product. The regulatory requirements that follow from this classification are substantial.

Atmospheric testing and monitoring

Before entry, the atmosphere inside the tank must be tested for oxygen levels, flammable gas concentrations, and toxic substances such as hydrogen sulphide. Oxygen content must typically fall between 19.5% and 23.5% for safe entry. Continuous monitoring throughout the cleaning operation is required, and workers must wear appropriate personal protective equipment including supplied-air breathing apparatus if atmospheric conditions cannot be guaranteed.

Permit-to-work and rescue provisions

A confined space entry permit documents the hazards identified, the controls applied, the personnel authorised to enter, and the duration of the work. A trained rescue team and equipment must be immediately available, not just on call. In many jurisdictions, including the Netherlands and Germany, the rescue plan must be rehearsed and documented. The standby person outside the tank must maintain continuous communication with those inside and must never enter the space alone to attempt a rescue.

What hazardous material and environmental regulations affect tank cleaning?

Tank cleaning generates hazardous waste streams including contaminated water, sludge, residual hydrocarbons, and chemical residues that are subject to strict environmental regulations governing storage, transport, treatment, and disposal. In Europe, the primary frameworks are the Waste Framework Directive and REACH, alongside national environmental legislation.

The substances previously stored in a tank determine how aggressively the environmental rules apply. Tanks used in petrochemical, refinery, or chemical processing environments will have contained substances classified as hazardous under European regulations. Before cleaning begins, the operator must identify all residual materials, classify them according to the relevant hazardous waste codes, and arrange for licensed disposal.

Wastewater generated during high-pressure water jetting cannot be discharged directly to surface water or sewer systems without treatment. Depending on the contaminants present, this may require an on-site water treatment system or collection and off-site disposal by a licensed contractor. Environmental permits may need to be obtained before the work starts, particularly for operations near groundwater or in environmentally sensitive areas.

For operations involving asbestos-containing materials, paint coatings with heavy metals such as lead or chromium, or radioactive scale in oil and gas tanks, additional specialist regulations apply and the work must be carried out by certified contractors using containment and collection systems that prevent any release to the environment.

How do ATEX and equipment safety standards apply to tank cleaning?

ATEX regulations apply to tank cleaning whenever work takes place in a potentially explosive atmosphere, which includes most tanks that have stored flammable liquids or gases. All equipment used inside or immediately adjacent to an ATEX-classified zone must carry the appropriate ATEX certification for that zone classification.

In Europe, the ATEX Directive (2014/34/EU) divides hazardous areas into zones based on the likelihood of an explosive atmosphere being present. Zone 0 indicates a continuous presence of an explosive atmosphere, Zone 1 means it is likely during normal operation, and Zone 2 means it is unlikely but possible. Tank interiors that have held flammable substances are commonly classified as Zone 0 or Zone 1 until they have been thoroughly cleaned, purged, and gas-freed.

Any electrical equipment, lighting, communication device, or powered tool used in these zones must be certified for the relevant zone and gas group. This extends to remotely operated cleaning equipment. For example, the MagTrack Mini robotic crawler is available as a certified ATEX Zone 2 unit, allowing it to be deployed in environments where conventional electrically driven equipment would pose an ignition risk.

High-pressure water jetting equipment used in tank cleaning must also meet the relevant machinery safety standards, including CE marking requirements in Europe. Operating pressures in industrial tank cleaning typically range from 500 to 3,000 bar (“7,250 to 43,500 PSI”), and equipment operating at these pressures must be designed, tested, and maintained to the applicable pressure equipment directives. Hose assemblies, fittings, and lances must be rated for the maximum working pressure of the system and inspected regularly.

What documentation and permits are required before starting a tank cleaning job?

Before a tank cleaning operation begins, you typically need a confined space entry permit, a hot work permit if any ignition-risk activities are involved, a risk assessment and method statement, an environmental permit or waste disposal plan, and documented equipment inspection records. The exact combination depends on the site, the substances involved, and the regulatory jurisdiction.

The risk assessment and method statement, often called a RAMS document, must describe the specific hazards associated with the tank, the cleaning method to be used, the sequence of work, the controls in place, and the emergency procedures. This document must be reviewed and signed off by a competent person before work starts and must be available on site throughout the operation.

Equipment used on the job must have current inspection and calibration records. High-pressure water jetting equipment operating in the 500 to 3,000 bar (“7,250 to 43,500 PSI”) range must be inspected at intervals defined by the manufacturer and by applicable pressure equipment legislation. Operators must hold valid training certification from a recognised body such as the EWJI, WJA, WJTA, SIR, or DIRV, depending on the country in which the work takes place.

Where environmental permits are required, these must be in place before any waste is generated. Waste transfer documentation must accompany all hazardous waste removed from the site, and copies must be retained for the period specified by the relevant environmental authority.

What happens if tank cleaning regulations are not followed?

Failure to comply with tank cleaning regulations can result in serious worker injuries or fatalities, significant financial penalties, criminal prosecution of responsible individuals and organisations, mandatory work stoppages, and long-term environmental liability. Regulatory enforcement in this area is active because the consequences of non-compliance are severe.

Confined space incidents are among the deadliest in industrial settings. Workers who enter a tank without proper atmospheric testing, adequate ventilation, or a rescue plan in place face a high risk of incapacitation or death from oxygen deficiency or toxic gas exposure. Regulators in most countries treat confined space fatalities as prima facie evidence of regulatory breach, and prosecutions routinely follow serious incidents.

Environmental violations carry their own serious consequences. Illegal discharge of contaminated tank cleaning water or improper disposal of hazardous sludge can result in large fines, remediation orders, and in some cases the withdrawal of operating licences. In the Netherlands, Germany, and across the EU, environmental enforcement agencies have the authority to issue immediate stop-work orders and to pursue civil claims for remediation costs.

Beyond the legal consequences, non-compliance damages operational continuity. A single regulatory enforcement action can halt an entire facility while investigations are conducted, creating far greater costs than the investment required to comply in the first place. For maintenance engineers and operators, understanding and following the applicable regulations is not only a legal obligation but a practical foundation for keeping operations running safely and efficiently.

How MagTrack Supports Compliant Tank Cleaning Operations

Meeting tank cleaning regulations is significantly easier when your equipment is purpose-built for the task. Our MagTrack robotic crawler system addresses several of the most demanding compliance requirements directly:

• ATEX Zone 2 certification available on the MagTrack Mini, enabling safe deployment in tanks with residual explosive atmospheres without requiring full gas-freeing before cleaning begins
• Closed waterblasting with vacuum collection via the integrated Blast Can, which collects both water and debris without leakage, supporting environmental compliance and clean-site requirements
• Remote operation reduces the need for personnel to enter confined spaces, directly lowering the risk profile of the operation and reducing the complexity of confined space entry permit requirements
• High-pressure capability up to 3,000 bar (“43,500 PSI”) with tools designed and certified to operate within applicable pressure equipment standards
• Modular design that can be configured with the appropriate tool for the tank geometry, including curved surfaces up to 3 metres (“approximately 10 feet”) in radius

Keeping your tank cleaning operations compliant, safe, and efficient starts with the right equipment and the right partner. Contact us to discuss how we can support your next tank cleaning project with solutions engineered to meet the regulatory demands of your industry.