Marking potentially explosive areas

Marking potentially explosive areas can be surprisingly challenging.

ATEX Directive 92/1992 Article 7 mentions that the entrances to areas that may contain potentially explosive atmospheres to a limit where they may be hazardous to the health and safety of staff must be marked with a warning sign that clarifies that there is a risk of explosion.

Marking areas in this way is good if the whole room, building, or area is potentially explosive. However, there are many instances where the extent of potentially explosive atmosphere is smaller. The use of EX sign in these areas makes these areas or rooms too high risk and limit the operation, and this way the EX sign suffers from devaluation.

I have created guiding signage in collaboration with my clients that not only inform of the risk of potential explosion but also specifies the cause of hazard and the extent of the area. These guiding signs are located near the operation that may cause a potential hazard. These signs are great for areas where potentially explosive atmosphere or area is only limited to one room, building, or area. Potentially explosive area can also be located inside equipment.

You can find an example sign for Flammable liquid storage on the Material page

Explosion Videos

Barrel explosion at a paint workshop

Fire at the Hospital of Turku

Dust explosion demo

Dust explosion in a slow film

U.R Chemical Safety Board produces material that shows how explosions happen, it is very demonstrative material!

Dust explosion at a sugar factory

Explosion at a laboratory

Fatal hot work explosion

Explosion at a chemistry lab


And finally something completely different – why batteries should be taped over before recycling

Lighting up a candle with 1,5V battery

It is worth investing in the safety culture at the workplace

In February 2012 I was at a safety training course. The training course was organised by DuPont Oy for their collaborative partners. DuPont is over 200 years old worldwide company, and a brilliant example of a company that invests in their safety culture. DuPont has approximately 65000 employees and the first product they made was gunpowder, so safety is at essence. The training course I attended took four hours and was filled with 100% valuable information. I made notes and will now share these with you because they will undoubtedly bring joy to people who work with safety.

Nine safety guidelines:

1. All injuries and work-related illnesses can be prevented

2. Company directors are responsible for safety

3.  All exposure to hazards during work can be managed

4. Safety is a condition of the employment contract

5. If work cannot be carried out safely, it will not be carried out

6. It is necessary to train all employees to work safely

7. Auditing must be carried out

8. All faults must be corrected as soon as possible

9. People are the most important element of a health and safety programme.

Other great principles and operating models:

  • Safety outside of work is an important part of the safety programme
  • Being proud of the good safety culture in the organisation is important
  • Acts, Decrees and guidelines will not be helpful if they are not considered in practice
  • Plan how you act and act like you planned. If you must deviate from the original plan, make a new plan.
  • If a potential risk of injury arises during work that was not considered in the risk assessment, stop the work and think of an alternative solution with your supervisor or the contact person of the client.
  • Report all hazards you notice and share your suggestions to improve safety
  • All hazards must be identified prior to starting work and risk assessment must be created to determine a hazard management plan.
  • Prior to starting maintenance work: lock, mark, verify, check, and after these you can start work.

Is old equipment still safe to use?

We get asked this often. Should an old piece of equipment in a potentially explosive area be replaced with ATEX equipment, even if the old equipment is still working?

Equipment that is not ATEX equipment but is still in use in a potentially explosive atmosphere or area can be continued to use safely IF:

  • The equipment has been suitable for ATEX areas in the past (there were EX areas even before ATEX directives).
  • They are suitable for the zone classification (0, 1, 2, 20, 21, 22) – zoning must be done for safety.
  • They are suitable for the hazardous substances in the premises (T1, T2, T3, T4, T5, T6 or dust ignition temperature). The most dangerous hazard must be identified.
  • The equipment has had a risk assessment (there are instructions for this).
  • The equipment is having regular preventative maintenance (preventative maintenance ensures that the equipment is in good condition).

Government Decree 1139/2016 §27 sets out transition requirements for old equipment

This law came to effect on 1st January 2017. Equipment that has been launched prior to this that fills the conformity requirements according to the regulations that were valid at the time, can continue to stay on market once this Decree comes to effect. Certificates of conformity of this equipment will continue being valid.

Government Decree 576/2003 §11 comes to effect on 1st September 2003.

Tools that were in used in potentially explosive areas before this Decree can continue to be used after this Decree comes to effect, if the employer has stated in a written risk assessment or an explosion protection document (that conforms to §8 in this Decree) that these tools can continue to be used safely in a potentially explosive atmosphere and that they meet the requirements regarding tools in Attachment 2 section A.

Tools that will be taken to use for the first time in potentially explosive areas after this Decree has come to effect must conform to Attachment 2 sections A and B, which sets out requirements for tools.

It is also important to note that new equipment must also fill out the requirements set out for old equipment, except risk assessment.

New equipment must be:

  • Suitable for potentially explosive areas and atmospheres
  • Suitable for the zoning classification of the area (0, 1, 2, 20, 21, 22) – zoning must be done.
  • Suitable for hazardous substances in the premises (T1, T2, T3, T4, T5, T6 or dust ignition temperature) Most dangerous hazard must be identified.
  • Equipment is having preventative maintenance (preventative maintenance ensures that the equipment stays in good condition).

Work tools and work gear for ATEX areas

What kind of work tools and gear are suitable for potentially explosive areas and atmospheres?

Gear and tools must be sparkless, have no hot surfaces and must not charge with static electricity.

Gear and tools must be durable for hazardous substances, such as flammable liquids, flammable gases and flammable dusts. This means that gear and tools for potentially explosive areas must have the highest temperature class or T classification (T1, T2, T3, T4, T5, T6) and explosion group (IIA, IIB, IIC).

Gear and tools must be suitable for potentially explosive atmospheres and areas. (0, 1, 2, 20, 21, 22)

So, what are these gear and tools?

  • Safety shoes
  • Antistatic work clothes
  • Antistatic underwear and socks
  • Antistatic shoe covers
  • Antistatic and explosion proof personal protection equipment (respiration mark, fall protection, hearing protection, etc.)
  • Explosion proof lights
  • Explosion proof mobile phone
  • Explosion proof camera
  • Explosion proof computer
  • Explosion proof tools or non-sparking tools (hammer, spanners, mixers)