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Animal Pathogens

This page has been amended in light of recommendation 47 [page 16] of the Health and Safety Executive's 'Final report on potential breaches of biosecurity at the Pirbright site 2007'.

Containment Requirements for Laboratories to be Licensed to Handle Defra Category 4 Pathogens under the Specified Animal Pathogens Order 1998

The following describes the physical features and operating conditions which would be required by Defra of any laboratory to be licensed to hold or work with Defra Category 4 pathogens. It is concerned with preventing the escape of pathogens from the laboratory and not primarily with ensuring the safety of the workers. It does not in any way limit the obligations placed upon employers and employees by the Health and Safety at Work etc. Act 1974 in general and COSHH in particular, or the Health and Safety Executive's duty to enforce these obligations. Extra precautions will often be necessary for the safety of the staff.

The laboratory - siting and structure

1. Whereas the laboratory need not be physically separated from other laboratories it should not be sited next to a known fire hazard (e.g. the solvent store) or be in danger of flooding.
2. The laboratory should be isolated by an air lock and provided with a suitably placed shower. Air locks and rooms must be ventilated by an exhaust air system. The air pressure in the laboratory should be monitored and displayed both within and immediately outside the laboratory. The laboratory should be maintained at a differential negative pressure of 75 Pascal's (Pa) (0.3 inches or 7.6 mm water pressure) to ambient. An alarm should sound if the air pressure falls below this.
3. The exhaust air must be filtered before discharge through two HEPA filters. The system must include a device to prevent back flow through the filters. The air intake should be protected by a single HEPA filter in case of power failure.
4. The laboratory must be sealable so as to permit fumigation.
5. The laboratory must be proofed against entry or exit of animals or insects. This is particularly important in the case of diseases which can be spread by insect vectors.
6. Effluent should be sterilised by a procedure known to kill the relevant pathogens. This procedure must be confirmed as having operated satisfactorily before the effluent is discharged to the public sewer, e.g. if heat sterilisation is to be used, temperature recording facilities should be provided to monitor the process. Since sterilisation and tests may take some time, it may be necessary to have more than one standing tank if work is to be carried out continuously. The standing tank(s) and recording equipment form parts of the facilities of the laboratory, so the Safety Officer is responsible for ensuring their proper functioning.

Laboratory facilities

1. The laboratory must be equipped with a Class I/II/III exhaust protective cabinet. All laboratory manipulations with live pathogens should be carried out in the cabinet in any mode with the exception of homogenisation which should be carried out with the cabinet in the Class I or Class III mode.
2. All waste biological material must be sterilised prior to removal from the laboratory. Therefore, each laboratory should have direct access to an autoclave which should have double doors. There should be no possibility of removing the load without the autoclave cycle having been completed. As soon as practicable after the completion of the autoclave cycle the load should be taken to an incinerator and immediately incinerated. Autoclaves should be monitored to ensure that time / temperature cycles are completed and records should be kept.
3. All material must be made safe before being removed from the laboratory unit. A double ended dunk tank filled with an effective disinfectant is required for the removal of materials that cannot be autoclaved. The dunk tank should be sealed during fumigation if the disinfectant is incompatible with the fumigant.
4. Each member of staff working in the laboratory must have adequate working space.
5. Specified pathogens should be stored in the laboratory and in suitable containers (depending on the mode of storage, frozen or freeze-dried) in a cabinet reserved for specified pathogens and kept under lock and key. A key should be available on demand only to nominated individual(s).

Protective clothing

1. Laboratory gowns must wrap over the chest and fit tightly at the wrists. Ordinary white laboratory coats are UNSUITABLE. Staff should have a clean gown for each uninterrupted period spent in the laboratory. Other types of clothing giving the same degree of protection may be acceptable.
2. Gowns must be autoclaved before they are removed from the laboratory.
3. Gloves must be worn for all work with infective materials and workers must shower before leaving the laboratory.

Safety Officer

NOTE: Throughout this document the term Safety Officer refers to a person having responsibility for work with specified pathogens.

1. A Safety Officer able to advise on infectious hazards, and a deputy, must be appointed or designated. The establishment may have a Safety Officer with general responsibility for such hazards. If not, an additional individual must be designated.
2. A Safety Officer should have appropriate qualifications and laboratory experience in working with specified pathogens.
3. The Safety Officer will act as adviser to the Head of the Department in all matters which may affect the containment of the pathogens, and should be authorised to stop practices considered unsafe, pending guidance when necessary, from the laboratory Head.
4. He or she will take control, implement first aid in, and investigate, all accidents in laboratories and take what other action he considers necessary.
5. Where their responsibilities are not sufficient to warrant full-time employment as Safety Officer, provided that they are readily accessible to the laboratory during normal hours, they may hold another appointment.
6. He or she will be responsible for the safe storage of specified pathogens and the maintenance of the inventory.
7. He or she will be responsible for organising the admission to the laboratory of cleaners and maintenance personnel and for the disinfection of any apparatus, etc. which is to be removed.
8. He or she will be responsible for advising staff on all aspects of the application of these Safety Precautions.

Training in handling specified pathogens

1. The Safety Officer will organise the initial training of staff in the safe handling of specified pathogens.
2. Training will cover, e.g. the correct use of safety hoods, exhaust protective cabinets, pipettes, syringes / needles, hot / cold rooms, centrifuges, blenders, freeze-driers, shaking machines, ultrasonic disintegrators, glassware and the disposal of contaminated protective clothing and laboratory materials.
3. Staff should only work with specified pathogens if they have some previous experience in microbiology and have had a course of training supervised by the Safety Officer.

Supervision

1. Work in the laboratory must, at all times, be carried out by or be supervised by a senior, trained and experienced member of the staff.
2. The supervisor will be personally responsible to the Safety Officer for the safety of the work actually in progress at any time, although he or she may not be responsible for the overall project.

Laboratory discipline

1. The containment area of each laboratory must be identified clearly with appropriate warning notices.
2. When unoccupied, the laboratory must be locked. The key(s) must be kept under the supervision of the Safety Officer, and released only to authorised persons. A key, however, should be kept at a secure control point, available at all times, in case of emergency.
3. In normal hours the supervisor will be responsible to the Safety Officer for ensuring that no unauthorised person enters the laboratory.
4. Only the Safety Officer or their deputy may authorise staff to enter the laboratory, and he or she will hold a list of names of personnel so authorised.
5. Unlisted persons (e.g. visitors, observers, cleaners or maintenance / repair personnel must not enter the laboratory unless they have received a signed statement from the Safety Officer that it is safe for them to do so.
6. The Safety Officer will be responsible for confirming when a laboratory and its apparatus have been disinfected.
7. The laboratory must be entered through a 'clean-side' changing area (locker room) separated from the 'dirty-side' by a shower and an airlock. All clothing, rings, watches, etc. must be removed into a locker. No food, drink, tobacco, make-up, etc. may be taken through the airlock. Clean protective clothing should be put on. The 'clean' and 'dirty' areas should be clearly distinguished physically.
8. On the way out, over garments should be placed in a bin on the 'dirty-side' of the showers and all remaining clothing also removed to a bin. The individual must then shower, transfer to the 'clean-side' and dress.
9. This procedure should be adhered to whenever, and for whatever purposes, the room is vacated.
10. All accidents or spillage of potentially dangerous material in the laboratory must be reported IMMEDIATELY to the Safety Office. EVERY SUCH INCIDENT MUST BE REGARDED AS A FULL MEDICAL OR ANIMAL DISEASE HAZARD.
11. The day-to-day cleanliness of the laboratory is the responsibility of those working in it. Only when the Safety Officer has confirmed that it has been disinfected can other cleaning / maintenance work be carried out.
12. At the end of a working day benches and working surfaces should be disinfected.
13. Work on specified animal pathogens must be kept separate at all times from other work in the laboratory.
14. Periodically, the rooms and everything in them must be fumigated with gaseous formaldehyde.

Handling of specimens

1. All in-coming packages which may contain specified pathogens must be opened by trained staff in the laboratory.
2. Senders should be advised that a liquid sample should be externally identified and sealed in a can filled with sufficient absorbent material wholly to mop up a spill. The can may, if necessary, be cooled in solid carbon dioxide or liquid nitrogen. Similarly solid samples should be double wrapped so that, in the event of the outer container rupturing, there can be no leakage of contents.
3. Chapter 6 of "Laboratory-Acquired Infections" by C H Collins (4th edition, Butterworth and Co. 1999) gives general advice on packing and unpacking specimens, but in the present context all such unpacking must be carried out in the containment facility.
4. Particular care must be taken when biological material which cannot be autoclaved, is to be removed from the laboratory. The Safety Officer must be consulted before unsterilised material is removed. Precautions must be taken to sterilise the outer surface of containers and to sterilise the material itself, as far as possible.
5. The movement of specified pathogens from an approved laboratory to any other premises is prohibited except under the provisions of a licence issued by Defra.

Security

1. It is imperative that the laboratory and animal rooms must be secure against intruders or vandals. An intruder alarm system must be fitted.
2. Security patrols, etc. must not enter laboratories, or animal rooms. If it appears that an adjacent fire or water hazard threatens the room then the Safety Officer should be informed immediately.
3. A key to the laboratory should be held centrally for emergency access but must only be released on the instruction of the Safety Officer or their deputy.
4. The Safety Officer must maintain a list of the specified pathogens used at the laboratory. This list must indicate the number of vials of pathogen under storage.

Standard Operating Procedures

1. SOPs must be written and issued to staff covering-
(i) receipt and unwrapping of incoming specimens;
(ii) handling of specified pathogens in vitro;
(iii) handling of specified pathogens in vivo (where appropriate);
(iv) disposal of all waste and surplus pathogens;
(v) storage of specified pathogens; and
(vi) emergency procedures.
2. All staff must be familiar with these SOPs and have access to them on a day to day basis. Adherence to the SOPs will be a condition of a licence issued under the Specified Animal Pathogens Order 1998 and they must not be altered without prior approval from the Defra licensing office. Any plans to amend SOPs must be forwarded, via the Defra inspector, to the appropriate HQ licensing office.

Animal room

NOTE: All relevant regulations in these Safety Precautions apply to any room in which animals are in contact with specified pathogens. There are, in addition, hazards arising from the natural diseases of animals which may be transmissible to man. Diseases can be contacted following bites, scratches, droplet infection or the bites of insect vectors. There are particular hazards associated with the generation of aerosols in animal rooms.
In addition to the staff utilising the animals, others may be engaged to clean and feed them and the Safety Precautions also apply to them.
1. DUST: Pre-filters are required to protect the HEPA filters and should be changed as necessary with the air-steam working. Used filters should be immediately placed into bags, autoclaved and then incinerated.
2. DRAINS: See THE LABORATORY - SITING AND STRUCTURE paragraph 6.
3. DEAD ANIMALS, BEDDING, DUNG etc.: see LABORATORY FACILITIES paragraph 2. Where autoclaving followed by incineration would create a radiological hazard, carcases must be first sealed in a suitable bag.
4. CAGES AND ASSOCIATED EQUIPMENT: must be autoclaved or disinfected before being cleaned and returned to store.
5. ESCAPES: in no circumstances should there be a direct exit to the outside. The Safety Officer and the licensing authority of Defra must be informed if an animal cannot be accounted for.
6. VERMIN: suspected or obvious infestation with insects or wild rodents must be reported at once to the Safety Officer and the licensing authority of Defra.
7. MONKEYS: the principal hazard in monkey handling not common to the handling of other animals is the risk of infection with monkey viruses which can produce serious disease in man. The established basic rules for handling must be observed.
8. RESPONSIBILITY: servicing of specified pathogen rooms in the animal house must not be carried out by general animal house staff. Suitably trained staff approved by the Safety Officer should carry out these duties under the day-to-day supervision of the person in charge of the animal house.

Arthropods

See seperate containment requirements for laboratories to be licensed to handle arthropods under the Specified Animal Pathogens Order 1998.

 

 

Page last modified: September 7, 2007

Department for Environment, Food and Rural Affairs