Lifesaving Precautions You’ll Need to Take for Safe Tank Cleaning Procedures

While we’d all like to think the potentially lethal risks of tank cleaning are well understood, it’s always worth revisiting the essentials. A concise overview of best practices, up-to-date safety guidance, and the latest equipment innovations can make a critical difference in safeguarding your team and ensuring the job is done safely and efficiently.

After all, a publication from the Health and Safety Executive (HSE) on hot work involving small tanks and drums highlights a sobering reality: “people have been killed or seriously injured” by explosions caused when welding or cutting tanks that still contain flammable materials or vapours.

The risks associated with physically entering a large tank for cleaning are even greater, and they come in many forms. This guide outlines some of the most critical hazards you need to be aware of, along with the key safety measures and equipment that can help mitigate them.

Risk 1

While nothing comes close to the essential step of a full, well-researched and actioned risk assessment, a major consideration to be aware of here is a simple one: has the tank been fully, meticulously emptied for cleaning to begin.

It may seem like common sense, but the presence of flammable materials, whether solid, liquid, or vapour, poses an immediate and serious risk to anyone using tools inside the tank.

Remember that remaining liquids may be heated by the work on the tank and can become explosive vapour.

In terms of recoverable product, the US Occupational Health and Safety Administration documentation for work on industrial storage tanks, in this case where petroleum and similar has been stored, recommends procedures covering:

  • Area protection, potential sources of ignition and electrical classification
  • Bonding and grounding
  • Entry onto fixed and floating roofs
  • Removing recoverable product through product lines, suction pump (fixed connections), by flotation through open inspection covers or connections, via vacuum pump or through inspection covers.

The safety of the job is only as good as the tank emptying process, making this a step no project can afford to overlook.

Risk 2

Turning now to the topic of safe entry into the tank itself, the International Tank Container Organisation (ITCO) provides a useful definition of what constitutes a confined space.

(Important note: Always verify whether information, including legal requirements, applies to your specific region, especially if you intend to use it for more than just background reference.)

According to ITCO, a confined space is typically defined as an area that:

  • Has adequate size and configuration for employee entry
  • Has limited means for access and egress
  • Is not designed for continuous employee activity

ITCO’s Safe Entry into a Tank Container publication offers a number of factors to consider when planning, or even considering whether to approve, entry to a tank:

  • The last cargo or substance stored in the tank
  • The relevant Safety Data Sheet (SDS), if applicable
  • The current cleanliness of the tank
  • The atmosphere inside the tank
  • The specific purpose of the tank entry
  • The duration the entry is expected to take
  • Whether alternatives to physical entry are available

It also includes examples of relevant safety equipment and procedures:

  • Gas or oxygen measuring device
  • Ventilation equipment and breathing equipment
  • Lighting
  • Protective clothing (masks, goggles etc…)
  • Harness
  • Alarm
  • Safety watch attendant

The ITCO information refers specifically to ISO tanks but the clear, concise thinking around procedures gives a useful overview. 

Risk 3

As briefly mentioned, the operator’s entry or work in a tank can cause flammables, including gases, to be stirred up. This presents an obvious risk of a fire and even possible death if the tank is not properly ventilated.

Thankfully, safe and high-quality ventilation is easier to source than ever due to continuous innovations and improvements in ventilation equipment for working on challenging sites.

Our article on Safe Working in Confined Spaces explains the key rules around ventilation and why it is often more effective to ventilate by pushing fresh air into the area.

Risk 4

Staying on the theme of dependable, purpose-built equipment for tank cleaning and other hazardous tasks, it’s vital to stress that only approved safety lighting and intrinsically safe electrical equipment should ever be used in enclosed spaces such as tanks. The risk of hydrocarbon recontamination creates a clear and present danger, and using non-compliant tools can significantly increase the risk of ignition, putting operators directly in harm’s way.

That’s why certifications, such as those under the ATEX Equipment Directive, along with formalised equipment selection requirements, are essential for work in hazardous areas. These standards ensure that all tools and lighting used are safe for their intended environment.

Find out more, including a breakdown of requirements by zone.

The Health and Safety Executive’s Hazardous Area Classification and Control of Ignition Sources document reminds those involved in directing or carrying out such work that the ATEX equipment directive was set out in UK law as the Equipment and Protective Systems for Use in Potentially Explosive Atmospheres Regulations 1996.

Find out more about the certification of SA Equip specialist products , including ATEX lighting and ATEX power distribution.

Equipment for the Toughest Environments

At SA Equip, we actively support our clients in achieving safe, effective ventilation, heat, and lighting results, delivering stand-alone solutions for the most demanding environments.

Our expertise dates back to the 1920s, with roots in the toughest shipping and oil industry conditions. Today, we bring that legacy of innovation and reliability to clients across aerospace, shipping, defence, utilities, pharmaceuticals, distilling, power generation and more.

We’re trusted worldwide for our ultra-reliable confined space ventilation equipment and the expertise that supports it. If you need guidance or equipment for your next project, please get in touch.