Standard Precautions For Laboratory Services 

Standard Precautions apply to blood, all body fluids, secretions and excretions regardless of whether or not they contain visible blood, non-intact skin, and mucous membranes. Standard precautions should be followed strictly since these general methods of infection prevention are design to reduce the risk of transmission of microorganisms from both recognized and unrecognized sources of infection in hospitals.

The laboratory staffs are at risk to all types of infections. Therefore, compliance to standard precautions and laboratory safety procedures are important to prevent occupational exposure. All staff must be oriented and updated in standard precautions and laboratory safety. Laboratory safety and infection control procedures are important to protect the staff and minimize accidental exposures to potentially infectious materials. Standard laboratory rules pertaining to safety and hygiene must be adhered to at all times when handling clinical specimen and in preventing exposures to infectious organism like the HIV and hepatitis virus via blood/ body fluids.

Newly- employed health care workers:

a.            All new staff in health care setting should be trained in laboratory safety procedures and to practice the standard precautions

b.            they should be screened for Hepatitis B infection/ status and given the appropriate vaccination if necessary.

 Protective Clothing

i.              Laboratory coats/ gowns/ aprons should be worn at all times when handling potentially clinical specimens and laboratory materials, and removed when leaving the laboratory. For procedures in which splashes may occur e.g. in the washing room, an impermeable apron is recommended. Change laboratory regularly at least once a week. Once contaminated to change immediately.

ii.            Wear disposable gloves when handling all clinical specimens. Remove gloves when answering the telephone, performing written work and on completion of work.

iii.           Wear mask, eye goggles or face shields if splatter or aerosols are likely to be generated such as activities of blending, sonicating and vigorous mixing. Carry out these activities in biological safety cabinet.

iv.           Contaminated laboratory coat, gown and other protective clothing should be soaked with sodium hypochlorite 1:10 for at least 30 minutes before washing with detergent and water.

Handwashing Facilities

i.              Wash hands after removing gloves and before leaving laboratory.

ii.            Sinks for washing hands should be available and located at the exit/ entrance of the laboratory

iii.           Adequate liquid soap and paper towels should be provided. Antiseptic detergents containing chlorhexidine may be supplied for washing hands contaminated by infectious material

General Precautions

i.              Keep laboratory as restricted area.

ii.            All workbenches and laboratory environmental surfaces (including drawers) should be made of smooth, non-porous material (e.g. Formica) and able to withstand regular disinfection.

iii.           Workbench tops should be regularly wiped with disinfectant.

iv.           The specimens for which special measures must be taken are blood, serum, unfixed tissue and body fluids. Urine, saliva and stool without overt blood staining present minimal risk. Specimens should be kept in a dirty area of the laboratory.

v.            Separate clean areas should be designated for books, forms and reports.

vi.           Serum, plasma and similar specimens should be preferably centrifuged in sealed bucket with translucent caps. If a breakage occurs in a centrifuge, the procedure should generally be abandoned, the centrifuge decontaminated by chemical disinfectant. Trained and informed staff wearing suitable protective clothing, as directed by the Head of Unit. It is not necessary to open the centrifuge bucket in a safety cabinet.

vii.          Centrifuge, including buckets, should be periodically disinfected (minimum once a week) or immediately when soiled.

viii.         Decontaminate any equipment that has been contaminated with blood or other body fluids with disinfectant, or autoclaved, whichever is suitable and according to the manufacturers’s recommendation.

ix.           Hands should be washed with soap and water after removing gowns and gloves, before leaving the laboratory and after handling material known or suspected to be contaminated.

x.            Mouth pipetting of any substance is strictly prohibited. Use mechanical pipetting devices for manipulating all liquids.

xi.           Do not recap needles and syringes to prevent needle stick injuries

xii.          All test tube racks must be decontaminated periodically (minimum once a week) or immediately when soiled.

Collection, Despatch And Reception Of Specimens

i.              All staff should be trained on safety and infection control measures regarding sharp injuries, blood and body fluid exposures

ii.            Specimens must be collected in robust screw-capped and leak-proof containers, which will stand upright. They should be properly labeled on both the specimen containers and request forms.

iii.           Blood specimens from patient with HIV/ AIDS should be sent to the laboratory by porters (and not via pneumatic tube transport system).

iv.           Contaminated laboratory forms should be discarded appropriately and replace with a new form.

Chemical Pathology And Hematology Laboratory

i.              Tests should wherever possible be confined to those which can be performed in an enclosed system, e.g. automatic analyzer

ii.            Automated machinery should be designed to avoid splashing and to have a closed system from specimen presentation to a safe discharge of effluent

iii.           If the apparatus requires servicing, preliminary disinfection of the entire system will be necessary.

Histopathology Laboratory

i.              The usual methods of fixation of tissue and smears are satisfactory for inactivation of HIV.

ii.            Wherever possible, tissues should be received in the laboratory as small specimens in fixative. For small biopsy specimens, 6-8 hours in 4% buffered formal saline solution would suffice and this time interval should satisfy most diagnostic needs. When a more rapid result is required, other methods of fixation, such as the use of heated formaldehyde solution, may suffice. No special precautions need be taken with fixed specimens.

Microbiology Laboratory

i.              Clinical specimens, which appear to have leaked, should not be processed (however it is subjected to procedures in respective unit). If another specimen could not be obtained, then the processing of this specimen should be left to the discretion of the Microbiologist.

ii.            Laboratory discard jars should be provided daily with freshly prepared 0.5% (1:10) sodium hypochlorite.