St 1 dust - Dangerous or not?

Hope all of you readers are doing well. It is the time of Diwali here in India and everywhere one can see people in the festival mood. Be careful and safe & have a wonderful Diwali.

Today I am trying to clear another misconception which I have come across while talking about St 1 dust. Many of our clients have told me that we are handling St 1 dust which is also the so-called "WEAK EXPLOSION" hence the risk is low. 

I always give them the example of Imperial Sugar Explosion in 2008 where a St 1 Sugar dust lead to 14 fatalities or Didion Milling Co. explosion in 2017 where St 1 grain dust was to blame for 5 fatalities, a dozen injuries and $1.8 million fine.

Combustible dusts are ranked into one of four classes i.e. St 0, St 1, St 2 and St 3. The level of explosion violence increases as we go from St 0 to St 3. The only dust that has zero risks of the explosion is a St 0 dust. However, all other dusts have an explosion hazard including the St 1 dust which can compromise containment on a piece of equipment, or blow out the walls of a building. Grains, Sugar, Fluor, etc. all fall in St class 1 dust.

ATEX - Compulsion, Option or Need of the hour?

Let us talk about another misconception which is rooting in the minds of some people.

If my company is not in Europe, why should we perform an ATEX risk assessment? It's not applicable in my country, why should I perform modification to the existing equipment and fittings?

All risk assessments should follow the simple hierarchical ‘Three Rules of ATEX/DSEAR’ approach:

1. Do not have a flammable atmosphere, but if you do...
2. Do not ignite it, but if you do…
3. Do not hurt anyone.

ATEX intentions are simply to provide a coherent focus for controlling risks from:

1. Substances with flammable, explosive and oxidising properties. ATEX also covers Corrosives and compressed gases.
2. Substances which can create potentially explosive atmospheres
3. Controlling work activities involving other substances that could create a fire or an explosion

If you are in a country where ATEX/ DSEAR is not applicable, then you can consider this as a good engineering practice that you are reviewing your plants' operations to establish a Basis of Safety for each and every operation.

Dust Explosion in Equalizer 2 - Have you seen it yet?

I am sure if you are a movie enthusiast, you would have already seen Equalizer 2. 

Did you happen to notice Denzel Washington creating a flammable dust cloud? 

The movie market was too saturated with Gas Explosions, so here comes a new type of explosion. The director took full advantage of the shot inside a bakery. 

Insights of a Dust Hazard Assessment (DHA)

Thank you all for your continuing support on my blog posts. Keep sharing with your friends and colleagues.

We have discussed a lot about dust explosion hazards and the risk to plant. The next question which stands is "How to carry out Dust Hazard Assessment (DHA)?" The intent of this post is for making you aware of how you can carry out a dust hazard assessment or if you have a third party doing it for you, then how to review the DHA report?