14 September 2018
The waste industry has many difficulties and risks, but none is more pressing or potentially disastrous than the threat of fire, warns Gareth Dibden.
WITH MANY waste products being highly flammable, risks of sparks and large quantities of combustible material present, waste management is one of the highest risk industries for fire incidents.
Fire guidance within the industry applies where a site houses more than fifty cubic metres of solid waste material that can act as a fuel source. However, you can apply the principles to smaller applications, or in areas where there is a significant hazard.
When looking for advice on fire safety, it is always advisable to firstly contact your local Fire and Rescue Authority (FRA), who can aid you on general fire safety. When faced with specific risks, such as explosive materials and other dangerous substances, the Health and Safety Executive (HSE) are an excellent source of advice from waste handling to fire safety.
As a waste site fire can potentially be an environmental hazard, it is vital that you talk with your environmental regulator to get their opinion on suitable precautions. It is also highly valuable discussing the needs of your site with your local Fire and Rescue service (FRS). While not compulsory, they will be able to give you a great deal of expertise in fire control, allowing you to tailor your own fire prevention and detection methods to best protect your site.
Insurers are also an important and often inexpensive way of obtaining technical advice on fire safety applications. It is in their best interest to mitigate the risks of fire on your site, keeping both the risks of claims down and your insurance premiums.
It is a legal requirement to carry out detailed assessments of the fire risk within any premises, including waste management. This then allows you to put in place controls and measures appropriate to your risks. Of special consideration within waste management is the use of industrial grinders and shredders – these often create sparks and act as an ignition source through the friction the process generates. These devices require special consideration for fire risk mitigation.
Technical standards for fire systems include British Standards (e.g. BS-5839), European Standards, building regulations and insurance industry standards. It is likely that you will need the advice of a fire system engineer to ensure that you have both appropriate protection and that the site is compliant to all pertinent standards. When in doubt, your local Fire and Rescue Service will be able to offer you advice on whether your fire system is compliant and fit for purpose.
Fire detection and suppression is a constantly evolving field, with many options available to help manage the fire risk at a site. With the nature of the risk, virtually all sites will need an automated fire detection system, with detection often combined with extinguishment and audio equipment to form a complete fire system. Options for detection include spark/infrared detection, flame detection, aspirating smoke detection and CCTV systems.
Depending on the nature of the risk, different detection technologies will be more appropriate than other alternatives. Broadly speaking, spark/ infrared detectors are very useful for detecting ignition sources within dark operating equipment, such as conveyor belts etc. While they do not offer much in the way of false alarm resistance (and so cannot cope with sunlight or artificial lighting), they are highly sensitive to hot spots and other ignition sources. Flame detectors are rapid response detectors, typically detecting flames within a few seconds of the fire starting.
They are ideal for detection in high-risk environments, such as those for volatile waste and for devices such as shredders or grinders. Flame detectors work through detecting the light created by a fire – units based on multiple IR bands typically offer superior performance in waste based applications. Finally, aspirating detection offers high responsivity against smoke sources, and is excellent for detecting smouldering fires. Difficulties in coping with dust and dirt make this technology more suited for cleaner storage environments.
Fire is a constant risk in the waste management sector, but with good planning and advice your installation can be safe.
The Waste Industry Safety and Health Forum (WISH) is an excellent source for material relating to all aspects of waste handling compliance. Their article on ‘Reducing fire risk at waste management sites’ is an excellent resource.
Environmental Services Association is an important regulator for waste management and a good source of information on compliance as is the Health and Safety Executive, which is a vital source for more specialist material risks. The Chartered Institution of Wastes Management is very knowledgeable on all aspects of waste management regulation and best practice.
Gareth Dibden is product manager at FFE Ltd. For more information, visit www.ffeuk.com
Case study- Winters Recycling
TO PROTECT its waste recycling facility from fire hazards, Winters Recycling Ltd has installed eight Talentum Dual IR optical flame detectors at its Hitchin site. Winters has been involved in waste management since 1986. Its primary businesses are skip hire, bulk earth moving and – at its Hitchin facility – recycling. The company is committed to reducing the environmental damage that can be caused by waste at landfill sites, so it recycles 95% of all of the waste it handles.
Talentum flame detectors are said to be ideally suited to waste handling as they can detect almost all types of flickering flames, not just hydrocarbon flames. This is especially important in the waste industry, where flames can originate from many different sources, including paper, plastic and even metals. By utilising infra-red (IR) sensing, Talentum detectors can also identify flames irrespective of any dust, steam or smoke present, and are immune to the effects of wind or draughts.
How flame detectors work is straightforward: optical sensors receive the IR and/or UV radiation emitted by the flames and a processor analyses the optical sensor signal waveforms and determines if they represent flames and, if so, accepts them. If the signals do not match the internal algorithms for flames then they are considered to be false sources and rejected.