Dust Flash Fire in a hostel - Who said that they don't see a dust explosion at home?

Happy New Year 2019 to all of you!

The Dust Flash Fire incident in Baptist University of Hong Kong has left all of us in shock with immense sadness and a heavy heart. Birthday party went wrong and ended in burning and injuring 12 students.

Five students were having a collective birthday party and were singing around the birthday cake. Someone in the group started throwing flour around, which probably got ignited by the burning candle and the flames reached the ceiling height leaving students with first and second degree burns on arms, legs and face.

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?

Risk Ranking:Essence of any Hazard Analysis

Recently, I was giving training on HAZOP and I got a question "Why do you say that our HAZOP is incomplete without risk ranking? We are doing the study since so long and no auditor or authorities have ever questioned us for the same." 

So this question has made me think about the situation Process Safety is facing. We know that oil & gas has developed more than other sectors including FMCG, Pharmaceutical, Chemical (Bulk & Speciality), etc. with far better standards for performing safety studies including PHAs. So, here I am writing this post to share the importance of risk ranking in any hazard analysis technique.

When is risk low enough : Risk Acceptance and ALARP

I would like to thank you all for continued interest in the blog posts. Keep reading and do like, share and comment. In this blog, we will be discussing what is the risk acceptance criteria and what is ALARP to define When is the risk low enough.

No activity is entirely free of risk in an industrial plant and hence it is imperative that safety risks are reduced to acceptable levels. The key question that remains is what level of risk is considered to be acceptable? 

Are you aware of the Dust Explosion Hazards in your facility?

I have written some blogs answering questions which I have received during training sessions or by email from our clients. Today I am sharing my experience related to the awareness level of manufacturing companies related to Dust Explosion. 

I made a recent visit as part of a non-profitable project to one of the most widely used Detergent and soap brands in India. As soon as I reached the gate of the plant, it was clear that I have entered a plant which hasn't been too serious about safe operations or safety of employees, as I could see the workers moving without any footwear leaving their feet marks in the raw materials spilled on the floor. There was so much dust and detergent in the air that I could taste detergent on my tongue till the next day of my visit.

Safe Practices for Sulphur Handling

Thanks for overwhelming responses on the recent blog post on Housekeeping and Secondary Dust Explosion & Relief Device Sizing.

I have recently published one of my articles in an Indian Magazine called "Chemical Weekly" in 10th July Edition. Attached below is a copy of the article.

Safe Practices for Sulphur Handling

The purpose of this document is to enable companies to establish reasonable prevention and protection measures, to eliminate or reduce the risks of fire and explosion inherent to handling of sulphur. This document is primarily concerned with the hazards arising from processing of solid sulphur, but also considers the major risks associated with handling sulphur in liquid form.

Hope you will find it useful. Do share the same with your friends and colleagues. Do follow the blog and keep writing to me for any questions and issues on himanshuchichra@gmail.com.

Housekeeping and Secondary Dust Explosions

Thanks for such brilliant response to my past blog on Relief Sizing. It really feels satisfying when it gives food for thought to people about their own plants. It is a much wider subject, hence all of us can hold different opinions on what is already there in terms of regulations and what is practically being done at the grass root level. In the end, my objective is simple and that is to make the community aware of some process safety aspects which can help them make their operations safer.

For this blog, I will be discussing the importance of housekeeping to prevent Dust Explosion or should I say Secondary Dust Explosions.

How many companies out there still utilise compressed air for cleaning of equipment surfaces and to blow off the settled dust from surface/ floor/ clothing?

How many of them still dry broom dust settled on the shop floor?

How many of you still don't know that the powder which is settled on equipment surface, shop floor, electrical fitting, etc., is combustible in nature and can result in fire/ explosion hazard in the plant?

How many of your plants have false ceilings and that hidden area is not being reviewed for any powder accumulation?

How many of you still use non-rated vacuum cleaners in plant areas to remove the spilt dust?

Relief Device Sizing and worst case scenario of Over-Pressurisation

Thanks to all for overwhelming responses to the recent update on Partial Inerting and Operator Earthing.

Looking at recent incidents that have happened in India, this topic was long due to being covered here on my blog. If we look at the Hyderabad Reactor Explosion or Tarapur Explosion or the more recent Moosapet Explosion, all have been suspected to be reactor explosion because of overpressurization.

The companies who are into manufacturing sector usually size their relief devices in the designing stage, when the process to be followed is not finalized and hence they assume a base solvent and size the relief devices for its vaporization in case of an external fire.

Now if we consider the T2 Laboratories accident where MCMT (Methylcyclopentadienyl Manganese Tricarbonyl) was being manufactured, an explosion which was equivalent to 1400 pounds of TNT was a case of a runaway reaction and killed 4 employees of T2 laboratories and injured 32 others. The impact was heard till 15 miles, the debris was found up to one mile away & buildings were damaged till one-quarter of a mile.

Operator Earthing - Are you doing it correctly?

Thank you guys for such an awesome response to my last blog post on Partial Inerting. It was made clear from the responses, that it is rather an unexplored topic in many parts of the world. Keep sharing your thoughts and keep sharing the blog with your colleagues, friends and students.

For today's blog post, I am picking up a basic concept of OPERATOR GROUNDING and what is the correct way to actually do it. There are many industries who provide Safety Shoes (maybe antistatic/ static dissipative) to their employees working on the shop floor, however, a substantial misconception regarding grounding practices exist in the industries that "If I have provided my operator dissipative shoes he has been grounded adequately." Also, there are many who purchase shoes with higher resistance to the ground then what is recommended by the standards.

Partial Inerting - A Cost Efficient weapon against Dust Explosion

Hey everybody, hope you are enjoying my blog and finding the information useful in your field of work. Today we are talking about a topic which is rather less explored and understood in many industries as of now i.e. "Partial Inerting".

Let's start first with understanding Inerting. Inerting is defined as the replacement of "oxidant" in a system by a non-reactive, non-flammable gas, to make the atmosphere within the system unable to propagate flame. Inerting may be achieved by using a non-flammable gas, which will neither react with the fuel nor with the oxidant. There are many gases used for inerting such as Nitrogen, Carbon Dioxide, Flue Gases, Noble Gases (Argon, Helium), etc.

P.S: Some material may react with these inert gases under some conditions. Hence, correct selection of gases is critical.

Now let's discuss the concept of PARTIAL INERTING to prevent dust fire and explosion. Partial Inerting means dilution of oxidising atmosphere with an inert gas but not up to the extent of LOC i.e. oxidant concentration lies between LOC and atmospheric concentrations. In other words, for partial inerting, the oxidising atmosphere (most often air) in which the explosible dust is dispersed is mixed with a fraction of inert gas (e.g. nitrogen) considerably smaller than that required for complete inerting (i.e. below LOC).