Survey finds 80% of UK ammonia refrigeration fails to meet dangerous substances standards

A survey of over 100 ammonia refrigeration systems operating in food manufacturing facilities in the UK found that under 20% met legislation covering dangerous and explosive materials.

The survey by consultant Stephen Gill Associates revealed that 30% of sites had either no risk assessment or inadequate ones for their ammonia refrigeration systems.

Principal Stephen Gill said: “Unfortunately, lack of understanding of the requirements is no excuse for lack of action in the eyes of the HSE, and indeed the insurance companies.”

The ATEX 137 Directive on explosive substances requires that all companies operating with areas, (including those containing ammonia refrigeration plant), classified as ‘Hazardous’ classify their production areas into zones and assess the risks both to their employees and their plant assets. While the majority of the sites in the survey had DSEAR (Dangerous Substances and Explosive Atmosphere Regulations) assessments for the rest of the site, the ammonia refrigeration plants had been ‘by-passed’ as they were considered ‘too specialist’, according to the consultancy.

It was not just the DSEAR/ATEX legislation giving operators problems to meet their legal obligations, the consultancy said. “The duties imposed by the Pressure Systems Safety Regulations 2000 (PSSR) relating to pressure systems for use at work and the risk to health&safety were also found to absent in many cases.”

The company discovered that many operators of ammonia refrigeration systems found it difficult to understand the standards that support the legislation. What is even more surprising is that many of the refrigeration contractors maintaining the systems also are gaving confusing or inaccurate advice to their clients.”

Certain aspects of DSEAR/ATEX can appear confusing but this legislation is all about personnel safety, allowing the workforce to understand the issues associated with their place of work, and ensuring that the number of accidents and injuries to persons operating in these industries is reduced.

The company found that many operators were using ammonia-based refrigeration systems for the first time due to changes in environmental laws around refrigerants. All this comes at a time when the HSE is putting a higher priority on health and safety of operations involving flammable materials.

Mr Gill added: “We are fortunate in this country to have a good safety record when it comes to ammonia refrigeration systems. Incidents are thankfully few and far between so we were surprised by the high number of sites with inadequate or inappropriate safety procedures in place”.

In the construction or reconfiguration of an industrial or marine refrigeration plant, the old question of whether to choose ammonia refrigerant or one of the halocarbon “Freon” refrigerants resurfaces, with a sincere attempt by the owner of the facility or marine vessel to do the right thing. On the one hand, ammonia has a strong and longstanding presence in the industry; on the other hand, the halocarbons do not carry as many safety and regulatory concerns that ammonia does. Both sides of the debate have well supported arguments for their position – which makes decision-making even more difficult.

Every difficult choice has a set of advantages and disadvantages, and the debate between “Ammonia vs. Freon” is no different. For example, one of the main advantages to ammonia, because of its overpowering odor, is that refrigerant leaks are “self alarming”. The main and most unfortunate disadvantage is that this “self alarming” nature of ammonia also attracts injury litigation should a refrigerant leak occur. On the other hand, the halocarbons are nearly odorless and leaks tend to go unnoticed by anyone outside of the maintenance group. That reduced risk of litigation is a great advantage. However, the fact that the halocarbons are nearly odorless creates a huge risk in that a large leak can silently displace the oxygen atmosphere in some areas of the plant, and cause a tragedy that ammonia refrigerant in a similar situation may not cause.

Here are a few facts that are worth considering:
- You may have heard it said that ammonia is a more efficient refrigerant; but a choice between ammonia and halocarbon will not substantially change your energy expense. That efficiency claim has to do with the refrigeration quality of ammonia per pound as compared to other refrigerants; but that is not to say that ammonia is more energy efficient. In fact, at low food freezing temperatures (-30F to -45F), most halocarbons have the advantage of smaller, less expensive compressors and lower compression energy than ammonia. At higher temperatures, ammonia tends to come out on top. However, in general, there are many more effective ways to gain energy efficiency in a refrigeration plant than in the selection of a particular refrigerant.

- Ammonia systems tend to be better maintained than halocarbon systems because leaks around valve stems, compressor shaft seals, and other leak-prone devices announce themselves due to the pungent odor – even at very low concentrations. A maintenance department cannot avoid due diligence with respect to ammonia leaks like they can in a halocarbon system where small leaks can go unnoticed or ignored simply because they have no odor, and are more difficult to locate.

At Focusun, we employ a team of seasoned design engineers who are focused on:
- Providing reliable refrigeration systems designed around ammonia, halocarbon or CO2;
- Offering the most reliable technology in any refrigerant media;
- Knowing the issues, advantages and disadvantages of every type of technology and how it affects the construction and operation of a refrigeration plant in any arena.