KITCHEN DESIGN NEED TO KNOW: Solid fuel appliances in commercial kitchens

Josper oven from Jestic

Solid fuel appliances such as tandoori ovens, charcoal grills and wood-fired pizza ovens are becoming more widespread in commercial kitchens these days, but until now there has been no official guidance on the safe usage of these items, other than that communicated by individual manufacturers. With concerns over carbon monoxide exposure capturing the attention of Britain’s Health and Safety Executive (HSE), FEJ assesses newly-published guidelines on the issue and tells you what you need to know if you’re planning to design solid fuel appliances into your kitchen.

Commercial kitchens can be pretty dangerous places. Water, fire, heat, gas — all of these things can turn a controlled working environment into a health hazard at the blink of an eye. There’s also another factor to worry about these days thanks to the popularity of contemporary appliances like wood-fired pizza ovens and indoor charcoal grills, and it comes in the form of carbon monoxide poisoning.

The risks associated with exposure to carbon monoxide gas are pretty obvious for anybody working in a commercial kitchen, but there have also been reports of this extending to members of the public as well, such as those in neighbouring properties, and that has led to the intervention of the Health and Safety Executive.

Following protracted talks with manufacturers and industry bodies, the HSE has now produced a special catering information sheet that gives operators guidance on the safe installation and maintenance of solid fuel appliances such as those described.

Published in collaboration with the Heating Equipment Testing and Approval Scheme, the Solid Fuel Association and the Hospitality Industry Liaison Forum, the guidance is designed to be read in conjunction with the ‘Ventilation of Kitchens in Catering Establishments’ document so that operators can assess whether their existing ventilation is adequate or, in the event they are planning the ventilation specification for new or refurbished kitchens, meets the requirements.

“Even moderate exposure to carbon monoxide can lead to serious permanent ill health, or even death,” warns Simon Frost, chairman of catering equipment trade body CESA. “Early signs of carbon monoxide poisoning are very similar to common ailments like flu, but can escalate quickly. It is for this reason that it is so important to ensure solid fuel appliances are installed, ventilated and maintained correctly.”

Although it is not a legal requirement to obtain advice before purchasing a solid fuel appliance, the HSE notes that seeking competent assistance on all technical matters relating to installation, ventilation, extraction and maintenance is less likely to result in costly mistakes being made.

The rules governing safe gas and electric appliance installation are carefully regulated whereas there is less experience with wood- and charcoal-fired equipment”

Organisations such as HETAS, B&ES, the Catering Equipment Suppliers Association (CESA) and the Catering Equipment Distributors Association (CEDA) are all well-placed to offer advice on the requirements for this type of combustion appliance.

Steve Loughton, managing director of Jestic, which imports the Josper grill and Wood Stone pizza ovens, both of which fall into the solid fuel category, agrees that the emphasis is on the operator to ensure that the appliances are both installed and operated safely and correctly given that in many cases they bring real flames and live cooking to the kitchen and dining areas.

“The rules governing safe gas and electric appliance installation are carefully regulated whereas there is less experience with wood- and charcoal-fired equipment,” he says. “It must always be remembered that these appliances only stop producing carbon monoxide when the fuel is fully extinguished. It is therefore imperative that operators seek competent advice on all technical matters such as installation, ventilation and extraction.”

So, what are the points that the HSE says operators need to consider for the safe installation and use of solid fuel appliances? Well, the first is design…

Wildwood LiverpoolDESIGN

When buying a solid fuel appliance, determine whether your flue or extraction system is designed and constructed from suitable material. The HSE notes that stainless steel can withstand the corrosive nature of products released during the combustion of solid fuel.

However, it notes that many kitchen extraction systems are made from galvanised steel, which is liable to corrosion. This could result in leakage of toxic combustion products, such as carbon monoxide, into other parts of the building or into neighbouring properties.

“If your extraction system is constructed from galvanised steel and you do not intend to replace it, seek competent advice on how this will impact on the nature and frequency of maintenance and inspection work,” it advises.

The extraction system and its component parts, including any induction fans, should be designed to withstand the high temperature and corrosive effects of any intended flue gases from the cooking appliance. Operators should ensure there is minimal risk of heat being transferred to any combustible materials close to the flue or ductwork.

The HSE states: “You should not attempt to alter a gas or electrical appliance to burn solid fuel. Only use appliances that are designed for indoor use. Those intending to use a solid fuel appliance at an outdoor event naturally need to be aware that using it inside a tent or gazebo can expose people to the risk of carbon monoxide poisoning, so ventilation is crucial.”

POSITIONING

When deciding where to site your solid fuel appliance, consider where fresh air is going to enter the room. Avoid areas where there is slow-moving or stagnant air. If the appliance is suitable for use under a canopy, ensure that the products of combustion can be effectively and safely removed — for instance, make sure that the canopy is not so high that it does not collect the combustion gases — and that monitoring equipment is in place to warn of any danger from products of combustion.

“To give general advice on positioning is very difficult when it comes to solid fuel appliances as every location will pose its own specific challenge,” says Jestic’s Steve Loughton. “The airflow in the room will be a key factor, but so will any extraction systems. Working with the equipment manufacturer, distributor or a specialist kitchen ventilation designer is vital and the only way to guarantee correct installation.”

Ultimately, say experts, as long as any piece of equipment that omits carbon dioxide and carbon monoxide is positioned under suitable ventilation, its location in a kitchen is flexible.

Solid fuel can also create sparks so we would further recommend a firebreak installed onto each item, which helps stop this passing into the ventilation system”

VENTILATION AND EXTRACTION

According to the HSE’s guidance, the termination point for the discharge of flue gases should not present any risk to employees or occupants of neighbouring properties. The flue should be located outside the building and terminated at a safe level. Operators are urged to seek advice from their local authority building control department to make sure they are compliant with the relevant requirements.

“If you use a solid fuel appliance that has a natural draught flue in a commercial kitchen with a mechanical extraction system fitted, there will be a risk that the products of combustion will be drawn back down the chimney or flue into the room,” states the HSE. “If you choose to have both systems it is very important that they have an equal supply of make-up air to compensate for combustion and removal of combustion products etcetera. A competent engineer will be able to advise you on how this can be achieved in your premises.”

Solid fuel appliances used in commercial kitchen environments generally use wood, wood pellets or charcoal to create the heat output required. And, as Neil Mantle of Mibrasa and Pavesi distributor Ascentia FSE notes, each of these will burn at different temperatures and create different flavours depending on their origin and quality.

“Each of these can omit carbon dioxide and carbon monoxide and therefore the equipment needs to be within a ventilation system just as with any gas-powered equipment,” he remarks. “Ventilation can be provided directly to each piece of equipment with its own vent or can share an extractor hood on a cookline with other equipment. Solid fuel can also create sparks so we would further recommend a firebreak is installed onto each item, which helps stop this passing into the ventilation system.”

MAINTENANCE, TESTING AND CLEANING

Extraction systems for commercial solid fuel appliances must be thoroughly examined and tested at least once every 14 months. Operators must also have an appropriate regular cleaning and maintenance programme to ensure that their extraction system continues to function properly.

“Maintenance, examination and testing should be carried out by a competent person,” notes the HSE. “Depending on the nature of the extraction system you may also need to use a competent specialist contractor for cleaning. You will find specific guidance in the B&ES guide TR/19 Guide to good practice — Internal cleanliness of ventilation systems.”
Like other credible brands within this sector, manufacturers Mibrasa and Pavesi offer full training on the usage, best practice and cleaning of any appliance post-installation. Looking after such appliances is often incredibly straightforward, says Ascentia’s Mantle.

“We want to make sure that each customer obtains optimum performance from their equipment and maintains it to ensure continued performance. Ashes should not be removed in a flammable or heat-deformable container — always use a metal bucket, shovel and ash pan. The ovens require little cleaning after service as they work at such high temperatures, burning carbon deposits as they operate. Daily cleaning would be as simple as removing ash deposits and weekly brushing out to ensure the cooking surface and vents are clear.”

MONITORING

Carbon monoxide gas can build up very quickly and people can be overcome without warning. The guidance advises that operators should fit a functioning audible carbon monoxide alarm complying with BS EN 50291 and have procedures in place to deal with evacuation if it goes off.

“Repeated activation of the alarm indicates a problem which should be investigated by a competent person before the appliance is put back into use,” the HSE notes. “Carbon monoxide detectors should be used and sited in accordance with the manufacturer’s instructions. If you opt for a battery- rather than mains-operated device you should ensure that the battery is tested periodically, as advised by the manufacturer.”

If possible, the appliance/alarm should be interlocked with any mechanical ventilation that is fitted. Operators should introduce robust procedures to make sure that the extraction system fan remains switched on until all solid fuel has been extinguished, even if there is nobody on the premises. “This will ensure that people in neighbouring properties are protected from any carbon monoxide that may be leaking from the premises,” says the HSE. “It will also ensure that the building is safe to enter for the next shift and can be safely accessed out of hours for example, in the event of an emergency.”

If operators do not wish to keep extraction equipment fans running 24 hours a day, the easiest way to make sure they remain switched on for a sufficient period of time is to interlock them to their carbon monoxide detector.

Zizzi - Intu Derby 033SELECTION AND STORAGE OF FUEL

Responsible suppliers and manufacturers will be able to advise you on the type of fuels suitable for your appliance, according to the HSE. “Only use recommended fuel unless you are certain that your extraction system can safely remove the products of combustion from alternative fuels,” it counsels. “By burning only the amount of fuel you need, you will minimise the amount of carbon monoxide produced. This will also help to keep your costs down.”

Jestic’s Steve Loughton reinforces the point that using the recommended fuel is crucial. “There are many types of fuel available but each will have its own different extraction requirements,” he says. “Only use the fuel which has been recommended and which the extraction system has been programmed for.”

Solid fuel should be stored in a dry and ventilated area. Requirements may vary depending on the quantity and type of fuel. Ultimately, concludes the HSE, operators should refer to the manufacturer’s or supplier’s storage instructions for specific advice.

What the law says

The Health and Safety at Work etc Act 1974

This act places duties on employers to ensure, so far as is reasonably practicable, the health and safety of their employees and that of persons not in their employment, such as customers, who may be affected by their business. This means that both workers and members of the public must be protected from the risk of exposure to carbon monoxide gas, whether your business is in operation or not.

The Workplace (Health, Safety and Welfare) Regulations 1992

These regulations require that employers provide effective and suitable ventilation in every enclosed workplace. This includes kitchens which need ventilation to create a safe and comfortable working environment. Mechanical extraction, via a canopy hood installed over the cooking appliances, can remove the fumes and vapour created by cooking and discharge them to a safe location.

The Control of Substances Hazardous to Health (COSHH) Regulations 2002 (as amended)

COSHH applies in commercial kitchens where solid fuel catering appliances are used. The Regulations set out a number of requirements to ensure risk is either avoided or reduced to an acceptable level. Carbon monoxide gas has a workplace exposure limit (WEL) which must not be exceeded. For further details look at EH40/2005 and the COSHH web pages.

Download the details

The ‘Preventing exposure to carbon monoxide from use of solid fuel appliances in commercial kitchens’ information sheet can be downloaded at: www.hse.gov.uk/pubns/cais26.htm

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