Falls from height account for a relatively large number of fatalities and major injury accidents investigated by the HSE (HSE2013b). Such falls:
• Are a major cause of fatal injury (20 %)
• Result in around 80 major injuries per year
• Result in an additional 230 over 3-day absences each year
• Can result in serious or even fatal injury even when the fall is less than 2 m
Table7.4summarizes the results of an analysis by the HSE of places from which employees fell.
Activities being carried out by at the time included:
• Cleaning or maintenance (from scaffolding/gantries, ladders, roofs, or false ceilings)
• Loading/unloading (from road transport vehicles)
• Gaining access to high areas to, e.g., change light fittings or clean/maintain plant (from FLTs where the worker was standing either on the forks or on a pallet mounted on the forks)
• Cleaning, maintenance, or sampling (from machinery/plant)
• Retrieving goods from high level (from racking)
HSE (2001a) makes the following food-industry-specific recommendations to prevent falls from height:
1. Cleaning
(a) Reduce cleaning at high level by alteration, modification, or maintenance of plant, for example, by ensuring effective extraction of dust and fumes.
(b) Modify high structures to reduce ledges and surfaces where dust can accumulate.
(c) Clean high structures from ground level, for example, with a foam jet cleaner.
(d) Where high access is required, ensure that a safe system of work is used. This will include provision of safe access systems, such as mobile scaffolds, which are constructed and used properly.
(e) Consider less common types of proprietary access equipment, such as inflatable platforms for silo cleaning.
2. Sampling or checking
(a) Change sampling or checking procedures so they can be carried out remotely from floor level.
(b) Relocate gauges and other equipment for measuring/monitoring/control to ground level.
(c) Sampling or checking is likely to be a regular feature of production. As such, where high access is required, permanent access steps/platforms should be provided, along with adequate handrails.
Table 7.4 Falls from height: analysis of places from which employees fell (after HSE2013b)
Fell from Percent of falls On vehicles, fell from Percent of falls
Ladders 40 Back of truck (e.g., off flat bed) 35
Vehicles/FLTs 17 FLT forks 31
Machinery/plant 10 Cab steps 13
Platforms 10 Top of vehicle 9
Stairs 8 Tanker steps 4
Roof/false ceiling 7 Other 8
Scaffold/gantry 4
Warehouse racking 4
3. Maintenance
(a) Where frequent high-level access is required to equipment or machinery, ensure that perma-nent access steps, ladders, handrails, etc., are provided.
(b) Where high-level access to plant, equipment or machinery is only required occasionally, ensure that safe access systems are employed, e.g., properly constructed and used mobile scaffolds.
(c) Ensure that workers do not use FLT forks, or a pallet mounted on the forks, as a quick lift.
Only properly constructed, fork-mounted cages should be used, as described in HSE (2013f).
4. Falls caused by slipping
(a) A good cleaning regime is essential on surfaces and equipment from which people might fall.
(b) Appropriate slip-resistant footwear is also required. Heeled footwear should be used on ladders.
(c) One-third of over-3-day absence injuries caused by falling in the food and drink industry occur on stairs. This is often due to stairs becoming slippery as a result of contamination with food product or water. Appropriate cleaning regimes and suitable footwear are therefore necessary requirements.
For further guidance on preventing accidents resulting from slips and trips, see Sect.7.3.4.
HSE (2001a) also describes the circumstances surrounding a number of typical fatal and nonfatal accidents involving falls from height. A useful bibliography provides the reader with supplementary reading material. It is noted that in 50 % of cases where a person falls from height, safe access has not been provided. Risk assessments for both capital and project plans should therefore include consid-eration of this possibility and the provision of safe, permanent access, or suitable portable equipment.
Retrospective provision of access systems, even portable ones, is more difficult to achieve.
7.3.3 Machinery
In recent years, accidents involving machinery have surpassed entry into silos as the third major cause of accidents in the food industry. Of the wide range of machines employed in the industry, conveyors, forklift trucks, and packaging machinery (particularly thermoform, fill, and seal machines, preformed rigid container packaging machines, and palletizers/depalletizers) are the most prone to accidents. In certain sectors, such as meat and fish processing, band saw accidents are relatively frequent.
Within many countries, the required health and safety standards of both new and existing equipment is strictly regulated under law. By way of example, we will consider the current situation in the UK as described by the HSE in several publications. In this country, all new machines, including own-builds, substantially refurbished machines from within the European Economic Area (EEA), and second-hand machines from outside the EEA should comply with the relevant “essential health and safety requirements” (EHSRs) of appropriate European Directives. These are:
• The Machinery Directive, implemented in the UK by the Supply of Machinery (Safety) Regulations2008, which came fully into force on 29 December 2009 (Regulations2008). The 2008 Regulation were subsequently amended in 2011.
• The Low Voltage Directive, implemented in the UK by the Electrical Equipment (Safety) Regulations1994, which came fully into force on 1 January 1997 (Regulations1994)
• The Electromagnetic Compatibility Directive, implemented in the UK by the Electromagnetic Compatibility Regulations 2006, which came fully into force on 28 June 2006 (Regulations2006)
A number of European standards have also been drafted to guide machine suppliers and users on how to meet the EHSRs. Purchasers can ensure that new equipment meets these requirements by specifying in purchase contracts that the equipment should comply with the relevant standards and then by checking on delivery that the Declaration of Conformity confirms this. HSE (2011d) provides food manufacturers with much useful advice relating to the purchase of equipment.
Machinery that complies with relevant Directives is CE marked. However, users should not automatically assume that it is therefore inherently safe; they should check for themselves that all relevant EHSRs are met.
In addition to the above requirements, the Provision and Use of Work Equipment Regulations 1998 (PUWER2011) imposes duties on employers to ensure that work equipment is:
• Suitable for the purpose for which it is used
• Maintained in an efficient state, in efficient working order, and in good repair
• Safe to use and able to be safely cleaned and maintained
• If new, able to meet the requirements of SMR
Users should use the safeguarding options for new equipment as a benchmark for existing machines. Where the standard of safeguarding is found to be lower than for new machines, a risk assessment should be carried out to see if the safety features can be upgraded without making production and maintenance tasks unduly more difficult. Improvements may also be needed in basic hardware, systems of work, training, and supervisory procedures. All improvements should form an integrated package.
It is clearly not possible here to describe the safety aspects of each type of machine used in the industry. Consequently, discussion is limited to conveyors and the three types of packaging machine listed above (forklift trucks were considered in Sects.7.3.1and7.3.2). In addition to the specific hazards associated with each individual machine, hazards of a more general nature should also be considered. By way of example, those associated with packaging machines are summarized in Table7.5.
7.3.3.1 Flat Belt Conveyors
Conveyors are responsible for around 30 % of machine-related injuries (HSE2001b, 2013c). Of these, 90 % involve flat belt conveyors, which include smooth, slatted, mesh, and woven belt types but not bucket, troughed, roller, screw, and rotating table types. The principal British Standards Table 7.5 Hazards of a general nature associated with food packaging equipment (after HSE2001d)
Hazard Nature of hazard Safeguarding measures
Electrical Ingress of liquid causing electrical shorting Electrical equipment should have the minimum ingress protection (IP) specified in BS EN 60529:
1992. Control gear—IP 54, control devices—IP 55. If devices may be cleaned by water—IP 65 Thermal Burns to operators Surfaces that reach a temperature of 65C or greater
should be insulated
Noise Hearing impairment Reduce by good design to the lowest possible level commensurate with the current state of the art Radiation Exposure to ionizing radiation from inspection
devices and nonionizing radiation from etching/coding devices
Reduce to a level such that devices can be assigned to Category 0 or 1 as defined in clause 7 and Annex D of EN 12198-1: 2000
Chemicals Various—depends on the nature of the chemical Good design and compliance with the Control of Substances Hazardous to Health Regulations 1998 (COSHH)
relevant to flat belt conveyors are BS EN 619 (BSI2002a) and BS EN 620 (BSI2002b). For details of these and other British standards, consult the BSI Web site (www.bsigroup.com).
About 90 % of conveyor injuries involve well-known hazards such as in-running nips, transmission parts, and trapping points between moving and fixed parts. Also, 90 % of accidents occur during normal, foreseeable operations—production activities, clearing blockages, and cleaning. HSE (2001b) recommends that the following hierarchy of safety measures should be considered for new conveyors;
these should also act as a benchmark against which existing conveyors are assessed.
1. Safety by design. Hazards associated with in-running nips and other trapping points should be eliminated by good design, e.g., by the use of lift-out rollers and by permanent guarding. The latter, which is welded in place or forms part of the structure, is the best option so long as it prevents the risk of injury and allows for cleaning and the safe clearing of product.
2. Fixed guarding. This type of guarding, which can be removed for maintenance and is secured using hand tools by screws, nuts, bolts, etc., can be used when the guard will only have to be removed infrequently. It should either enclose the danger area or prevent access by ensuring a suitable distance to any danger area—see BS EN ISO 13857 (BSI2008). The disadvantages of fixed guards are that they may not be replaced properly and that access for cleaning may be restricted. Where frequent access to transmission parts is required for adjustment or lubrication, this should be possible without having to remove the guard.
3. Interlocking guards. These are guards fitted with coded magnetic interlock switches, which prevent the machine running when they are open. They should be used where guards need to be removed frequently (e.g., daily) for cleaning purposes and clearing blockages, etc. Advantages include ease of access; disadvantages include the need to maintain the interlocks in good working order. Interlocks should be hygienically designed. Their control system and interlocking integrity should comply with the requirements of EN ISO 13849-1 (ISO2006). Control guards can be used where safety conditions permit (e.g., the operator cannot be trapped in the danger zone, interlocking is to the highest possible reliability, and there is no hazard during the rundown time). These start the machine when they are closed and can be used to reduce downtime.
4. Tripping devices. Tripping devices, which may be either mechanically actuated (e.g., trip bars, safety mats) or electrosensitive (e.g., photoelectric) devices, should only be considered where it is not practical to safeguard by other means. These devices should stop the machine before an operator or part of an operator can enter the danger zone. The integrity of mechanical and electrosensitive tripping devices should comply with the requirements of EN ISO 13849-1 (ISO2006).
5. Two-hand control. This is not considered suitable for safeguarding conveyors because it does not offer protection to others who may be in the vicinity.
6. Other design issues. The design of all belt conveyors should take the following into consideration:
• Safe methods of clearing blockages and in-use cleaning (e.g., spray nozzles).
• Safety at conveyor start-up. It may not be possible for an operator located at the control panel to see all people who may be at risk. In such cases an automatic start-up warning should provided, which would allow an emergency stop control to be operated before the conveyor starts up. Alternatively, mirrors or other viewing aids should be considered.
• Suitable selection of belt materials. Smooth belts can have different levels of grip, which can increase/reduce the risk of being drawn in. Particular care should be taken where such belts are installed adjacent to each other.
• The need for trays and drainage to capture drips from belt lubricants.
• Suitable enclosure/protection for motors, switches, etc., to prevent the ingress of water, cleaning chemicals, etc.
• Documenting safe methods of work, cleaning methods, etc., in the instruction handbook.
7.3.3.2 Thermoform, Fill, and Seal Packaging Machines
Nearly 50 serious accidents involving thermoform, fill, and seal (TFFS) machines were investigated by the HSE between 1997 and 2001. A third of these were major injury accidents involving amputation and broken bones. About half the injuries were caused by guarding failures at the two main hazard areas, the forming dies and the cutters that separate the continuous packaging into individual packs (HSE2001c,2013c).
An analysis of the accidents investigated by the HSE revealed the following principal causes:
• 36 %—guards removed, failed, or inadequate
• 19 %—guarding not provided or fallen into disuse
• 17 %—unsafe systems of work, especially during maintenance
Injury occurred most commonly on manually loaded horizontal, short bed machines, which have insufficient space between the forming and sealing dies to fit tunnel guards that comply with the separation distances specified in BSI (2008).
New TFFS machines should be safeguarded using the techniques described in BS EN 415-3 (BSI 2000b). This standard also covers horizontal and vertical form, fill, and seal machines, bag fill and seal machines, and carton erect/form, fill, and seal/close machines. Safeguarding against the major hazards can be achieved by the following means:
• Tunnel guards over the forming and sealing dies should have reach distances in accord with BSI (2008).
• Where the depth of the opening exceeds 120 mm, as well as the guard extending 850 mm, a pictogram should be attached warning operators of the hazard of reaching into the machine.
• If it is not possible to achieve the required reach distances for the guards, the following options should be considered: trip guard, trip guard with deterring device, light-sensitive trip device, linked automatic guarding, and automatic guard.
7.3.3.3 Preformed Rigid Container Packaging Machines
This wide-ranging category of packaging machines accounted for 45 serious accidents investigated by the HSE between 1997 and 2001. The principal hazards are mechanical in nature, moving parts that give rise to shearing, puncture, cutting, and entanglement hazards. An additional hazard is the ejection of containers or container parts, particularly where pressurized filling is carried out.
The following hierarchy of safeguarding measures is recommended in HSE (2001d):
• Avoid mechanical hazards by design.
• Fixed guards.
• Interlocked guards.
• Electrosensitive protective equipment (ESPE).
• Adjustable guards.
• Protective structures.
Safety distances for guards are given in BS EN ISO 13857 (BSI2008).
On high-speed rotary machines and packing or unpacking transfer mechanisms, the operation of an emergency stop or a power failure can cause the loss of operational stability or the dropping and/
or breakage of a container. Machines should be designed to minimize the hazards resulting from such eventualities. Any cutting tools should be capable of being removed and replaced safely.
HSE (2001d, 2013c) list a large number of machine-specific hazards and safeguards that were originally set out in BS EN 415-2 (BSI2000a). The reader is referred to either of these publications for further details.
7.3.3.4 Palletizers and Depalletizers
Most palletizer/depalletizer accidents happen when operators or maintenance personnel enter the machine and become trapped between fixed and moving parts such as transfer heads, sweepers, and pushers. Entry into the machine is necessary for adjustment, clearing of blockages, cleaning, and maintenance. Additional hazards also arise from falling loads, sudden movement of jammed product or pallets when they are freed, and by movement due to the failure to dump stored energy in pneumatic and hydraulic systems. The HSE investigated 30 serious and fatal accidents involving palletizers and depalletizers between 1997 and 2001.
The safeguarding requirements for new plant described in HSE (2001e,2013c) are based on those set out in BS EN 415-4 (BSI1998). Entry into the machine should be via a dedicated route other than the pallet load entry/exit openings. Doors provided for this purpose should be fitted with interlocking devices with guard locking, and openings should have suitable electrosensitive protective equipment (EPSE) acting as a trip. In practice, a perimeter fence with interlocked personnel doors and photoelectric safety systems at the pallet entry and exit points should be employed. Inside the machine, all movable parts that are accessible should be protected by fixed guards.
Following the entry of a worker into the palletizer or depalletizer, it should only be possible to restart the machine by an intentional action at a control device located outside the danger zone.
Trapped key interlocking devices or presence-seeking devices should be provided in order to prevent the machine being restarted by a third party while a worker is still inside it. It should also be possible for an operator located at the main control panel to ensure that there are no people in a position where they may be put at risk.
The entry of an operator through the entry or exit points for pallet loads, unit loads, or empty pallets should be prevented by at least one of the following methods:
• Electrosensitive protection equipment. These systems can discriminate between a person and a load on the basis of, e.g., length. Alternatively, they can be designed to detect the direction of motion and the size of an object. If these do not match those of a pallet load, a stop command is initiated.
• Interlocked moveable guards. These are unlocked when a pallet is ready to be discharged. The pallet then pushes the guards open. Once the pallet has passed through the resulting opening, the guards then close automatically with, for example, the aid of springs. The next cycle can only start when the lock on the guards is closed.
• Fixed guarding. This should be at least long enough to accommodate two loaded pallets. The first pallet can only be removed when the second pallet, which acts as a barrier, is in position. This method should only be used in low-risk applications on palletizer exit points as no protection is provided at start-up.