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

We’d all like to hope the potentially lethal risks around tank cleaning are pretty well known BUT every single one of us can always, always benefit from a ‘coffee break’ overview of the essentials, current info and the latest equipment advice.

After all, a Health and Safety Executive publication around hot work on small tanks and drums warns that “people have been killed or seriously injured” by explosions caused by welding or cutting a tank with flammables including vapour inside.

The risk, then, caused by actually entering a large tank for cleaning is even greater and exist in a number of forms.

This quick read guide introduces some must-see dangers and mitigations…

TANK CLEANING PROCEDURES: RISK 1

While nothing – including this blog – 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 sounds like common sense but the risk of flammable materials, be they solid, liquid or vapour, being present is an immediate and substantial 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.

And 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.

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

TANK CLEANING PROCEDURES: RISK 2

Turning now to safe entry into the tank itself, the International Tank Container Organisation (important note: always check if information including legislative and other requirements refer to your location or not if using for more than just background information) has a useful definition of ‘confined space’:

• Has adequate size and configuration for employee entry

• Has limited means for access and egress

• Is not designed for continuous employee activity

Its 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/ substance, the Safety Data Sheet (if applicable), tank cleanliness (as above), atmosphere inside the tank, purpose of the tank entry, the length of time the tank entry should be permitted and if any alternatives to tank entry exist.

In includes, of course, examples of relevant safety equipment and procedures:

• Gas or oxygen measuring device

• Ventilation equipment (see below) and breathing equipment

• Lighting (see below)

• 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. 

TANK CLEANING PROCEDURES: 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. 

Also, our Safe Working in Confined Spaces blog explains the key rules around ventilation and why it is often more effective to ventilate by pushing fresh air into the area.

We’re trusted across the world for our ultra-reliable confined space ventilation equipment and supporting expertise. For help to equip your next project just ask.

TANK CLEANING PROCEDURES: RISK 4

Staying on the theme of dependable, purpose-made equipment for tank cleaning and other hazardous jobs, it cannot be emphasised enough that only approved safety lighting or intrinsically safe electrical equipment can be used in enclosed spaces including tanks.

The risk? Hydrocarbon recontamination presents an obvious danger for the operator.

That’s why certifications, in this case the ATEX equipment directive, as well as formalised equipment selection requirements (see here for further information broken down by zone) apply to such hazardous work areas.

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.

Information about the certification of SA Equip specialist products – including ATEX lighting and ATEX power distribution – is easily found on our website. We’ll also be happy to clarify or help with any questions you might have.

EQUIPMENT FOR THE TOUGHEST ENVIRONMENTS

We’re much more than just an equipment ‘supplier’. We actively help our clients safely achieve optimal ventilation, heat and lighting results in challenging environments using stand-alone solutions.

What makes SA Equip different? We bring almost 100 years of pacesetting service and knowledge – with a foundation in the most extreme shipping and oil industry environments – to global clients across aerospace, shipping, defence, utilities, pharmaceuticals, distilling, power stations and more.

This means SA Equip portable air, light, heat and power products have been proven in challenging conditions offshore, in the air and beyond for almost a century.