The protection of food against contamination from pests is a key prerequisite within a good manufacturing practice (GMP) system. Preventive methods include staff awareness training, adequate proofing, an effective pest control programme, minimising harbourage and potential food sources, and suitable control of incoming ingredients and materials that could support pest infestation. The major emphasis, however, must always be prevention.
22.1 The Prevention of Damage by Pests Act 1949 requires an occupier of any land or buildings to notify the local authority of rodent infestation. It also requires all local authorities to take steps to ensure that their district is free from rats or mice.
22.2 The Food Safety Act 1990 made it an offence to sell food that is unfit for human consumption or contains foreign bodies, for example pests, parts of pests or droppings. EU Regulation (EC) No. 852/2004 on the hygiene of foodstuffs requires that ‘The layout, design, construction, siting and size of food premises are to … permit good food hygiene practices, including protection against contamination and, in particular, pest control’. To do this requires measures including:
- proofing of entrances and other access points;
- insect screens on open windows;
- electronic fly killers (EFKs), otherwise known as insectocutors;
- minimising harbourage, especially good stock rotation of dry goods;
- regular surveys by competent pest control contractors; and
- the use of appropriate baits and chemical pest control measures.
22.3 The principles of pest control are to limit food supply, access or movement of pests, and potential harbourage. There are two types of pest control: physical and chemical. Physical control methods are preferable as the pest is caught, cannot further contaminate the food and there is no risk of chemical contamination of food. Physical methods also include proofing of the building. Physical methods are not always completely effective, and a combined approach with chemicals may need to be used. A major concern with chemical control is that the pest may not be killed at the point of contact, for example ingestion, and could die later and possibly contaminate the food.
22.4 Incoming ingredients and materials should, as appropriate, be thoroughly inspected for signs of pest infestation as part of the quality control programme. All materials should be stored (see 22.10) to minimise the risk of infestation.
22.5 The most effective contribution towards infestation control is maintaining good housekeeping standards, for example controlling accumulations of food and paper debris, keeping gangways and passages clear, removing redundant equipment and materials from the manufacturing areas, and ensuring good stock rotation. External housekeeping is as important as internal housekeeping. External housekeeping includes:
- keeping vegetation short and not allowing vegetation to grow close to buildings;
- managing waste, ensuring all external waste areas are enclosed and they do not encourage pests nor provide harbourage;
- ensuring that leaking taps are not providing a source of water for pests to drink;
- ensuring waste building materials, redundant equipment, pallets or wooden boxes are not allowed to accumulate close to manufacturing units; and
- ensuring attention is given to other activities in the vicinity that could attract pests, for example adjoining farming activities, food manufacture or storage, or waste handling.
22.6 All premises should either have personnel trained in pest control or employ a professional infestation control organisation for regular inspection, advice and treatment to deter and destroy infestation. An outside contractor should be accompanied on his/her visit by an appropriate staff member. It is important at the end of each visit to have a closing meeting with the contractor to discuss key points such as the current level of pest activity, contractor recommendations on proofing or general housekeeping, areas where the contractor has not been able to gain access to examine bait points and whether any actions recommended in previous visits have been addressed appropriately by the manufacturing organisation or if further action is required and if the documentation in the pest control file is up to date.
22.7 Site inspections should be regular and reports of each inspection should be kept on file to be available for future reference if required (see 22.16).
22.8 Care should be taken to ensure that bait spillages cannot pose a risk to any foodstuffs being manufactured or stored in the vicinity. Wherever practicable rodent baits should be based on fatty or waxy substrates. Risk assessment of individual locations should be undertaken to determine whether loose or solid bait materials will be used. The risk assessment should also assess whether only non‐toxic baits should be used in internal areas. Private standards differ in their prescriptions on this point and their requirements should be determined in order to ensure compliance and thus approval. Standards, such as the British Retail Consortium (BRC) Global Standard for Food Issue 7, prescribe that only non‐toxic baits can be used within production or storage areas where open product is present except when treating an active infestation (see 22.16).
22.9 No substances or application methods should be used in infestation control that have not been approved under the Control of Pesticides Regulations 1986 as amended 1997. Due attention should be given to risks of cross‐contamination, for example by spillage of grain bait, inadequate cleaning after chemical application to control pests and dispersal of tracking dust. Care should be taken to protect all materials, product, packaging, utensils and surfaces in contact with food from residual contamination by pest control substances.
22.10 Goods and equipment should always be stored at least 50 cm from adjacent walls to facilitate cleaning and inspection for rodents and insects. Drains and gutters should be fitted with screens and traps to prevent pest entry. Attention should also be paid to drains and drain pipes that could allow pest ingress.
22.11 Except where there are risks of dust explosions, all production areas should be supplied with electrical insect killing ‘knock‐down’ devices. These should be sited in areas of minimum light intensity for best effect, but should not be sited directly above any tanks, hoppers, conveyors, processing equipment, filling machines or open food.
22.12 Depending on insect type and the products being produced, pheromone traps may be used, where appropriate. Insect ‘knock‐down’ devices should be fitted with suitable catch trays that should regularly be inspected and emptied when necessary (see 22.16). These devices should be left switched on at all times even after production has finished and the premises vacated; this is particularly important during the summer months. The ultraviolet (UV) light tubes on these units should be shatterproof in design and replaced at least annually. The glass tubes should be suitably controlled under the site’s brittle material control procedures. The annual bulb change of the UV light should be recorded, plus any damage or breakage to the light bulb and the actions taken (see Chapter 19, 19.36–19.42).
22.13 Domestic animals, for example cats and dogs, should be excluded from manufacturing and storage areas. This is mainly accomplished by keeping all doorways and other entrances closed. Staff should never feed or otherwise encourage stray animals. Waste skips and waste storage areas should be adequately controlled to prevent attracting feral cats, especially on meat‐processing sites.
22.14 Birds and insects must be excluded from all production and storage areas. To do this effectively, all apertures in the roof or its eaves, or the walls should be identified and either closed off or suitably screened. Drains and guttering should also be fitted with screens and traps to prevent pest access. Doors and windows similarly should be suitably protected, for example by use of air curtains, strip curtains and netting (see 19.11).
22.15 Where there are already birds in the confines of the premises, they, and their nests, must be removed. In the UK there are legal requirements under the Wildlife and Countryside Act 1981, elsewhere due regard to the requirements of the various bird protection agencies must be observed.
Pest Control Programme
22.16 The pest control programme should address the following steps:
- Assessment: The pest control programme can be undertaken internally by suitably trained staff, or a contractor could be engaged to undertake either part of or the entire pest control programme. If an organisation is using a pest control contractor, they must determine the suitability of the contractor and should assess criteria including the following:
- if the manufacturing organisation’s customers have an approved list, then one of these approved organisations must be used to deliver the pest control programme;
- the proximity of the pest control contractor to the manufacturing site, the resources available and the response time in the event of a problem, information such as number of employees and holiday cover, and ease of communication, for example mobile telephone numbers and weekend cover;
- whether the pest control contractor can demonstrate technical competence, that is, in the UK is a member of a recognised association such as the British Pest Control Association (BPCA; http://www.bpca.org.uk) or National Pest Technicians Association (NPTA; http://www.npta.org.uk), and the individual operators have formally recognised training and/or qualifications and if required have been on refresher courses to keep their knowledge and skills up to date;
- the experience of the pest control contractors in the food industry sector and the specific types of food produced and whether they can supply references from current clients;
- the type of contract the pest control operator provides and whether it meets internal/external requirements in terms of types of pests covered and the frequency of visits, that is, the ability of the contractor to undertake a complete pest risk assessment, undertake routinely the pest survey required and provide a clear report of their recommendations and actions required. The contract needs to address the frequency of the contractor’s field biologist quality assurance surveys as well as the number of routine pest control visits; and
- evidence of the financial viability of the contractors and their current level of insurance cover with regard to product, public and employer’s liability. A copy of current insurance certificates for the pest control contractor should be retained within the pest control manual.
- Protocol: The pest control contractor should provide a pest control manual that includes the following:
- a health and safety risk assessment for the pest control contractor employees identifying any health and safety concerns. Material safety data sheets must be retained along with Control of Substances Hazardous to Health (COSHH) assessments for the insecticides or rodenticides and other substances that the pest control contractor could use to demonstrate compliance with the COSHH legislation (or the equivalent outside the UK). These data should also be available for non‐toxic baits if they are used as well as toxic materials. The pest control contractor in the UK must demonstrate compliance with the Control of Pesticides Regulations 1986 as amended in 1997 and the EU Biocides Regulation No. 528/2012;
- a contract for the pest control service, based on risk assessment, identifying the minimum number of routine inspections, emergency call‐out requirements, quality assurance inspections and the types of pests controlled, that is, the scope of the pest control programme. The risk assessment should also consider external risks based on location, incoming and in‐process materials and products produced, for example stored product insects will be a factor with dry materials, and the combination of physical and chemical pest control methods that will be used. The pest risk assessment may also identify the number of field biologist visits required per annum. The initial risk assessment must determine the locations for toxic and non‐toxic rodenticide. Toxic bait should not be used in areas where materials and products are subject to open storage, processing or other associated manufacturing areas unless a risk assessment has deemed that the risk level is such that the potential contamination hazard is constantly controlled to an acceptable level. If toxic baits are used as a result of an active infestation, they must be adequately controlled to prevent contamination;
- a dated bait plan, pheromone trap and/or EFK plan identifying the premises or site layout and where the baits or equipment are located. The bait points/EFK should be individually numbered and identified on the plan, and this number should correspond to the actual number on the bait box or item of equipment. The bait boxes should be robust and tamper proof, that is, hard plastic rather than paper box design, and also be secured to prevent loss or accidental damage. In the event that a bait box is found to be missing, the quality control manager or designate must undertake an investigation to identify the whereabouts and/or potential risk to the product and action must be taken as appropriate. The bait plan should also include areas of roof void and any baiting that has been undertaken. It should be signed off by both the appropriate member of staff from the manufacturing site and the appropriate person from the pest control contractor company. The bait plan should then be reviewed and re‐signed and dated on an annual basis to demonstrate that verification activities have been undertaken and that there have been no changes. In the event of changes, the bait plan will need to be reissued and authorised by the two personnel as previously described;
- a checklist for bait points and EFK, which identifies the status of each point on each inspection for easy reference and analysis of trends. The coding is usually R = rat, M = mice or I = insects. The EFK should be individually identified. The trays should be routinely inspected and data collated, including the numbers of flies, the types of flies and any trends noted. Action must be taken as appropriate;
- inspection reports, which should be maintained by the pest control contractor for each inspection identifying the pest control status, any evidence of pests, proofing or poor housekeeping and any recommendations. The reports should be numbered for easy cross‐referencing. Any required corrective actions need to be signed off by the pest control company to demonstrate completion. The reports should be routinely analysed by the quality control manager for trends;
- current membership certificates for the BPCA or equivalent;
- current insurance certificates; and
- training certificates, which should be retained to demonstrate the competence of the operators undertaking pest control and those undertaking quality assurance activities.
- Implementation: The pest control contractor needs to implement the agreed programme, and personnel on the site need to be vigilant to ensure that they continue to check for evidence of pests. The manufacturing organisation should never effectively delegate responsibility for pest control to the contractor, partly because it is site personnel who are most likely to see evidence of pests or the pests themselves. Staff must be made aware that they must report evidence immediately to their line managers so that the manufacturer is actively managing its pest control system and an emergency visit can be arranged with the pest control contractor. The pest control contractor should always be accompanied by a competent member of staff to ensure any issues identified are suitably communicated during the routine visit or an emergency visit if required;
- Evaluation: The effectiveness of infestation controls/the pest control programme and the compliance of the pest control contractor with the requirements of the contract both need to be evaluated. An audit of the pest control procedure needs to be carried out as part of the internal audit process (see Chapter 11). The management control of the design, maintenance and proofing of buildings is critical to the pest control programme. It is not enough to have a pest control contractor visiting the site if the doors are left open or do not fit close enough to the floor, fly screens are broken or drains, roof spaces, piping and ducting allow access. The effectiveness of the premises hygiene protocols should also be assessed and their potential impact on the pest control programme. If potential food sources are not adequately controlled, then this will reduce the effectiveness of the pest control programme. Trend analysis is an important element of this evaluation.
22.17 The quality control manager and their nominated deputy must be responsible for the implementation of the pest control programme. They should be responsible for undertaking a review at regular intervals with the pest control contractor to ensure that the required level of service is maintained, for example the number of visits complies with the contract and that the programme provides effective control, there is a hazard data sheet in the file for each chemical control used and so forth.