Safety measures in clinical laboratory

Safety measure can be defined as then means of freedom from danger risk or threat of harm, injury or loss of personnel whether caused deliberately or by accident. While laboratory is a building or part of a building or the place equipped to conduct scientific experiment, tests investigations, observations etc. anything suggestive of a scientific laboratory.

Safety in the laboratory is based on understanding and respect not fear, the regulation or intended to help us work safely with chemical and samples in the laboratory, these guidelines covers ordinary hazard and apply to any laboratory experiment to be carried out. Before beginning any experiment, be sure the procedures are understood and have the necessary information at hand.

Safety rules in the laboratory

  1. Long hair and billow clothing must be confined when in the laboratory. Shoes are mandatory, sandals or open toed shoe are not allowed, even if socks are worn, shorts and skirts must cover the knees.
  2. All laboratory workers must know the location and proper use of all laboratory safety equipment including eye wash, safety shower, fire extinguisher, and telephone, they should expected to locate all safety equipment.
  3. They should know how to exit the laboratory via two different exits, in the laboratory in the event of emergency.
  4. All accident including contacts with chemicals, cuts, burns or inhalation of fumes must be taken for immediately attention with first aid, but if severe should be referred to the hospital.
  5. Laboratory equipment and work area must be cleaned after finishing work each day and also weekly cleaning.
  6. Highly flammable chemicals should not be taken top open flames.
  7. Use every precaution to keep all chemicals of your skin and clothing out of sensitive part of the body like nose, mouth and eyes and away from flames, it is strictly forbidden to eat or drink anything including water in the laboratory.

Minimizing equipment and technique related hazards

Pipettes

Mouth pipette must be banned at all times , pipetting devices should be inspected routinely for leakage and service and replaced as necessary. When discharging infectious materials from the pipette, it is important to minimize the formation of aerosols, the pipette should not be forced out but left in the pipette, care should be taken to avoid bubbling when mixing liquid with pipettes, it may be advisable to discharge the liquid unto the side of the container contaminated pipettes should always be discharged into disinfectant fluid which is prepared daily. Broken and chipped pipette should be discharged.

Hypodermic needles and syringes

These are the most common hazardous piece of equipment in common use, surveys have shown that at least one quarter of overt accident which result in infection were caused by these instrument, many inoculations result during experiment s. others occur during transfer of infected materials by syringe , many needle stick accident occurs when the needle is being disconnected from the  syringe so that the blood may be discharged into specimen container gently to avoid  heamolysis and also recapping of syringe needles. It is important that used needles are disposed in harden sharp containers which are then autoclave before discarding.

Centrifuge

Infectious materials may be dispersed by a centrifuge either through broken tubes or other means such as through the of  the tubes and caps, sealed centrifuge bucket should be used when  centrifuging  infected materials, tubes should be capped and they the buckets should be balanced carefully to avoid vibration which may lead to breakage , materials containing agent which are particularly like to cause infection should be centrifuge in sealed centrifuge bucket.

Pouring infectious materials

Pouring of the supernatant after centrifuging stool or urine specimens is common practice, these fluids are usually poured into disinfectant, the hazard may occur or arise production of aerosols.

Collection and labelling of sample

A large number of the specimens are transported by various means between different hospitals and laboratories every day. During transit the containers or the package enclosing them maybe handled by many people. The container may also be lost or stolen or even involve in an accident and damaged or broken. Therefore the collection, packaging , transport and unpacking should be strictly related.

Collection of specimen 

Container

In most laboratories, disposable screw capped 25ml bottle have replaced glass containers, specimen contains must be sufficiently robust to withstand the stress they are likely to meet and leak proof reusable container must remain leak proof during their lifetime.

Blood

Traditionally blood is collected with syringes and needles and then expelled into plastic containers which result in external contamination. Needle stick injuries are particularly likely to occur in recapping the needle and this practice should either be discourage or a safer method of resheating should be used.

Faeces

Faeces are probably hazardous materials other than blood, the specimen are often collected by the patient who is rarely instructed on the proper method of collection, patients tends to fill the container with faeces, this may result in leakage or the cap caning off, moreover, when such as container is opened , a violent broadcast be result,  patient should be told to remove a pea sized portion with the spoon provided to insert it into the container and screw cap on tightly.

Other specimen

Sputum specimen are probably less hazardous to handle because of the increasing incident in developed countries, apart from some viruses the organism present in sputum are rarely infectious. Nevertheless the risk from urine are minimal, although a small proportion of patients may excrete salmonella typhi, leptospires, hepatitis and other specimen such as pus and aspirated fluid are collected by professional staff which minimizes the risk of external contaminations.

Labeling specimen and container

Labels and stickers used should be self-adhesive for obvious reasons, there is much controversy about danger of infection and “high risk” label, these are often used for specimen where there is a special risk such as HBV or HIV. The problem is that these labels may give a false sense of security to staff who should handle any specimen as potentially infectious with dangerous pathogen specimen labelled “Danger of infection” should be placed in self sealing plastic bags, pins and staples should not be used as they may prick the hands of the person handling the bag, request forms should be separated from the specimen.

Transportation of specimens

Transport within hospitals- Code of practice stipulates the leak proof (bottom and seams not leak) trays or boxes should be provided for the transport of specimen from ward to the laboratory, and these should be able to withstand autoclaving or overnight exposure, staff carrying the hand wash frequently. The taking of specimen into canteens and kitchens should be forbidden.

Transport between hospitals

Require that “special” secure transport boxes with secure transport boxes with secure lids, these must be capable of withstanding autoclaving and prolonged exposure to disinfectant. These boxes should be inspected daily for leakages and decontaminated and washed out at least weekly.

By air or by flight

Before any material is sent to another country by air mail, the sender and the receiver must ascertain that it is acceptable to the authorities of that country. The material should be placed in a water tight “primary container” which is taken in a water tight container “secondary container” and the whole packed in an “outer container” all containers must be approved by the postal authorities. The following documentation are required (1) an International Air Traffic Association Shippers Certificate for Restricted article (2) Labels giving content description and quantity of Infection of Infectious substance  (3) Green custom labels (4) Officials address label.

Contaminated laboratory waste

  • Laboratory waste should be separated into colour-coded container, the recommended colour are
  • Yellow- for incineration
  • Light blue or transparent with blue inscription –for autoclaving (but maybe incinerated subsequently).
  • Black – for normal household waste local authority refuse collection
  • White or clear plastic – soiled linen

There are three methods or treating contaminated laboratory waste sterilization by autoclaving, chemical disinfection and incineration. The first two are laboratory processes, incineration involves the transport of materials off-site, sterilization and disinfection are not synonymous, sterilization implies the killing of the all micro-organisms disinfection kills most micro-organisms but depends greatly on the chemical used.

Roles of safety officers

All laboratory should have at least one person who is well vast in safety practices and who understand and can advise the management on its legal responsibilities in respect of the health and safety of its employees under the UK health and safety regulations 1998 employers have a legal obligations to appoint as safety advisor “competent” persons who will advise and assist in protective and preventive measures against accident and ill health caused by their work. The suggested duties of a safety adviser (officer) includes

  1. Advise the management on the formation of the a safety policy
  2. Assist scientific staff in drawing up standard operating procedures (SOPs) that incorporate safe practice s
  3. Carry out safety audits and inspections
  4. Investigate accident and incident and ensure they are reported and documented as required by law
  5. Ensure that protective clothing and equipment are in good order
  6. Ensure that hazardous materials are correctly labelled and stored
  7. Liaise with emerging services

Emergency plans

One or more SOPs should be drawn up for dealing emergencies like

  • Natural disaster (fire, flood etc.)
  • Serious contamination of premises
  • Accidental exposure of staff to infection
  • Emergency medical treatment
  • Injuries into dangerous occurrence
  • Epidemiological investigations

Personal and general laboratory safety

  1. Never eat, drink, or smoke while working in the laboratory.
  2. Read labels carefully.
  3. Do not use any equipment unless you are trained and approved as a user by your supervisor.
  4. Wear safety glasses or face shields when working with hazardous materials and/or equipment.
  5. Wear gloves when using any hazardous or toxic agent.
  6. Clothing: When handling dangerous substances, wear gloves, laboratory coats, and safety shield or glasses. Shorts and sandals should not be worn in the lab at any time. Shoes are required when working in the machine shops.
  7. If you have long hair or loose clothes, make sure it is tied back or confined.
  8. Keep the work area clear of all materials except those needed for your work. Coats should be hung in the hall or placed in a locker. Extra books, purses, etc. should be kept away from equipment, that requires air flow or ventilation to prevent overheating.
  9. Disposal – Students are responsible for the proper disposal of used material if any in appropriate containers.
  10. Equipment Failure – If a piece of equipment fails while being used, report it immediately to your lab assistant or tutor. Never try to fix the problem yourself because you could harm yourself and others.
  11. If leaving a lab unattended, turn off all ignition sources and lock the doors.
  12. Never pipette anything by mouth.
  13. Clean up your work area before leaving.

Chemical safety

  1. Treat every chemical as if it were hazardous.
  2. Make sure all chemicals are clearly and currently labeled with the substance name, concentration, date, and name of the individual responsible.
  3. Never return chemicals to reagent bottles. (Try for the correct amount and share any excess.)
  4. Comply with fire regulations concerning storage quantities, types of approved containers and cabinets, proper labeling, etc. If uncertain about regulations, contact the building coordinator.
  5. Use volatile and flammable compounds only in a fume hood. Procedures that produce aerosols should be performed in a hood to prevent inhalation of hazardous material.
  6. Never allow a solvent to come in contact with your skin. Always use gloves.
  7. Never “smell” a solvent!! Read the label on the solvent bottle to identify its contents.
  8. Dispose of waste and broken glassware in proper containers.
  9. Clean up spills immediately.
  10. Do not store food in laboratories.
  11. Wash hands before leaving the lab and before eating.

Mechanical safety

  1. When using compressed air, use only approved nozzles and never direct the air towards any person.
  2. Guards on machinery must be in place during operation.
  3. Exercise care when working with or near hydraulically- or pneumatically-driven equipment. Sudden or unexpected motion can inflict serious injury.

Conclusion/recommendations

Safety measure in the laboratory is of great importance which cannot be over emphasized to prevent the loss of life and property in the laboratory, personnel should adhere to safety rules and regulation to make smooth and safe running of the laboratory to prevent accident in the laboratory.

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