DSS123: Ask Me Anything on Combustible Dust Safety in Australia & New Zealand with Dr. Chris Bloore & Dr. Jim Munro-Part 2

In today’s episode, we go into Part Two of an Ask Me Anything session inside the Dust Safety Academy. Dr. Chris Bloore and Dr. Jim Munro co-hosted the session and answered listener questions about the role of housekeeping in dust control, challenges with dust collection systems, certification of equipment and technical committees.

Jim said that each state in Australia has its own legislation for what is called occupational health and safety or workplace health and safety but, to the best of his knowledge, it doesn’t directly reference explosive atmosphere or hazardous areas.

“If you have an accident of some description, or an incident, or an accident particularly where people are injured, then those acts and associated regulations come into play in relation to investigations and prosecutions,” he says. “There are very hefty penalties that are involved, and these can be applied right up to the directors of the company. And these had an effect on people’s minds a bit more in recent years.”

Where Can You Get Samples Tested?

Chris said that at one time, you could have samples tested at Simtars in Queensland or TestSafe Australia in New South Wales.

“Both those facilities have stopped testing to the best of my knowledge,” he says. “So I’ve directed people towards the Dekra facility near Shanghai… There are also labs in the States and in Germany, of course, where Dekra’s parent company is. But it is comparatively expensive – you’re looking at several thousand dollars for a suite of tests. But if you’re doing design work, you need to know a few things like PMax and KST for the maximum pressure and the rate of pressure rise of a dust explosion. And you probably want to know minimum ignition energy to get some idea of whether or not you need static precaution, and maybe minimum ignition temperature may be required as well.”

Have There Been Any Notable Large Loss Incidents Involving Combustible Dust in New Zealand and Australia?

Chris said that he wasn’t aware of any large loss incidents in Australia- he has investigated a few smaller explosions and fires that cost a few thousands or tens of thousands of dollars, but not millions.

“However, in New Zealand, we’ve had some big ones,” he says. “In ‘89, a spray dryer plant was completely ripped apart. The barrel of the chamber was ripped out of the building and jumped about 200 millimetres in the air, dropped back crooked, and did a lot of damage to the building. The whole thing needed replacement.

In April ‘93, we had a twenty million New Zealand dollar fire following an explosion in a plant in New Zealand. The explosion did very little damage. The flexible connectors on the plant were made of kevlar, and a little bit of the stitching around the flexible connectors broke, and a tiny trace of soot was found on the outside of the connector. But otherwise, it held together. Unfortunately, it blew out some inflatable rubber cuffs around the butterfly valve, set fire to the ceiling of the building, which then set fire to the roof, burnt its way across the building in about 25 minutes and destroyed two spray dryer tops in an adjacent building.

“It was about a 20 million dollar rebuild in ‘93. So although the explosion did relatively little damage, probably, to be honest, if there had been no fire, probably two or three hundred thousand dollars tops. But the fire did a lot of damage. Again, nobody hurt.

Chris recalled an April 2005 incident involving a small fire that set off a massive explosion in a large spray dryer and a June 2005 hot work incident in a dairy factory that burned down half the factory and put people out of work.

“Now, one of the interesting things that I observed with insurance is that the major cost of an incident is likely to be the loss of production from the factory while it’s out of action,” he says. And people will insure against that. But typical excess or deductible on the insurance policies in New Zealand is between five and 10 million dollars. In other words, the owner of the equipment pays the first five to ten million dollars of each claim, and they’re insured for losses above that. That’s to keep the insurance premiums manageable. But it gives you an idea of the sort of money that this can cost.”

What Are Housekeeping Standards Like?

According to Chris, when it comes to housekeeping, the food industries tend to be very good.

“The feed industry is not so much,” he adds. “It’s apparently unknown for livestock to get food poisoning. This is news to me because I thought they got sick just like people. But the feed industry’s hygiene standards generally seem to be quite poor in my experience and therefore there’s a hazard for dust explosions.”

Two other issues Chris has come across include:

Using blow-down guns to dispose of powder. “It ‘cleans’ but of course, it doesn’t really. It simply relocates the product and disperses it. So you’ve got yourself a problem.”
Dust collectors for fugitive dust. “You might have a bag filling or a bag dumping operation, and you’ll have a dust extraction system going to a small dust collector. And these are quite often put into warehouses, often with no signage or warning that it’s got a problem. They usually come with an explosion panel and are sometimes put up only a short distance away from a concrete wall or a metal skin wall. And there’s no thought given to the hazard if it was to go bang.”

Can Equipment That’s Certified Using NZ or Australian Standards be Sold and Used Elsewhere in the World?

According to Jim, all major countries in the world now are involved in the IECEx Scheme. A condition of entering the scheme is that participants agree to accept test reports to the standards from other countries through all the bodies in the scheme. They must also commit to accepting the assessments done by manufacturers.

“The first one works reasonably well,” he says. “There have been some hiccups with the second exercise, with the manufacturers where some things are different. What happens is that in a few countries of the world, the IECEx certificates that have been issued can be used direct-to-market. Australia and New Zealand are two of those countries. There are a few others, but not many. The majority of countries have their own certification schemes. In Brazil, essentially it is just a rubber-stamping of the IECEx certificate. And even in Europe, where they have ATEX, it is now common practice for anybody over there that issues a certificate for ATEX that they also issue a certificate for IECEx.”

Conclusion

Chris acknowledges that there are challenges when it comes to universal certifications and standards.

“It’s jumping around between Metric and US units, and with different certifications, and that even within Germany, you’ve got the VDI and EN, which are often but not always the same or similar. And you’ve got the earlier adoption of the risk-based approach by the Europeans, and the slower adoption by the US. And it’s been something of a moveable feast, so trying to keep up with their own spin being tricky.”

Jim agrees but has seen progress.

“I think we’ve done pretty well with exceptions to the standards when I was Chairman of the IEC TC 31 Committee for 15 years. I started in about 1987 or ‘88. At that time, IEC standards were not really adopted by many countries in the world nor used as a basis. Even at that time in Europe, they were pushing ahead very hard to develop their own standards because they needed it for the ATEX system. But in that time I was Chairman, we really turned that around with the exception of the US. But now even the US adopts the IEC standards but in design approach.”

If you would like to discuss further, leave your thoughts in the comments section below. You can also reach Chris Bloore and Jim Munro directly:

Email: chris@drchris .co.nz , [email protected]

LinkedIn: https://www.linkedin.com/in/chrisbloore/ https://www.linkedin.com/in/jimmunrointernational/

If you have questions about the contents of this or any other podcast episode, you can go to our ‘Questions from the Community” page and submit a text message or video recording. We will then bring someone on to answer these questions in a future episode.