Working in a Laminar Air Flow Workbench

Guidelines recommend that Low Risk Level compounding be done in a ISO Class 5 environment such as a LAWF. The High Risk categories require that a laminar flow hood be located in a Class 100,000 (Category 1) or 10,000 (Category 2) controlled area. In any of these cases, however, working in a laminar flow hood is not sufficient to ensure sterility. The hood does not provide sterility - just an ultraclean work area.

Products will be placed in the hood for assembly or compounding that are either sterilized before hand or will be sterilized by filtration while in the hood. Personnel carrying out these procedures must use techniques to minimize the potential contamination (microorganisms, particulate material, pyrogens) possible during these manipulations. Aseptic technique can be defined as the sum total of methods and manipulations required to minimize the contamination of sterile compounded formulations.

The following are considered minimum requirements for good aseptic technique:

• Conduct all manipulations inside a properly maintained and certified laminar flow hood. Allow the laminar flow hood to operate for at least 30 minutes before use in order to produce a particle free environment. Maintain a designated "clean" area around the hood.
  
  
• Remove all jewelry and scrub hands and arms to the elbows with a suitable antibacterial agent. Sterile gloves are worn in addition to scrubbing.
  
  
• Wear lint-free clothing or clothing covers, head and facial hair covers, and a mask.
  
  
• Clean all flat surfaces of the hood with 70% isopropyl alcohol, or other antibacterial scrub such as benzalkonium chloride solution, working from top to bottom, then from back to front.

View a video demonstration on cleaning a
laminar flow hood

• Assemble all necessary supplies in the hood checking each for packaging damage, expiration dates, and particulate material. Use only pre-sterilized needles, syringes, and tubing for medication transfers.
  
  
• Remove the dust covering from supplies before placing them in the hood.
  
  
• Be sure there are no objects between the HEPA filter and the sterile surfaces, and that there is adequate space between objects. Place the smaller supplies closer to the HEPA filter and larger supplies farther away from the filter.
  
  
• Swab all surfaces that require entry (puncture) with 70% isopropyl alcohol or betadine solution. Avoid excess alcohol or lint that might be carried into the solution.
  
  
• Give close attention to hand position and the direction of air flow over injection ports or objects being manipulated. Minimize hand movements within the hood.
  
  
• To assemble needles and syringes, peel back the protective coverings and attach the needle and syringe, twisting to lock in place. When handling syringes and needles, be sure not to touch any surface that will come in contact with the sterile solution. Only the exterior of the syringe barrel, plunger tip and needle cap or sheath may be safely handled.
  
  
• Do all manipulations at least 6 inches inside the outer edge of the hood. Do not remove the hands from the hood until the compounding procedure is complete and the final inspection of the formulation has been made.
  
  
• Examine all formulations before removing them from the hood.
  
  
• Place all syringes and needles in puncture-proof containers and dispose of them according to institutional procedures.