To lay down the procedure for cleaning of Glassware.
2.0  SCOPE:
This shall be applicable to the Glassware of Quality Control Instrument Lab.
3.1  Technical Assistant/ Helper.
3.2  Q.C Analyst.
4.1  Manager-Quality Control.
5.1  Glassware.
5.2  Dry lint free cloth (2 pieces).
5.3  Purified water.
6.1  Cleaning of glassware, which has contained hazardous materials, must be solely undertaken by experienced personnel.
6.2  Most new glassware is slightly alkaline in reaction. For precision chemical tests, new glassware should be soaked several hours in acid water (1% solution hydrochloric acid or nitric acid) before washing.
6.3  Wash glassware as quickly as possible after use if it is not possible then the articles should be allowed to soak in purified water.
6.4  General cleaning: (Daily/ after every use)
6.4.1        Before starting cleaning of glassware remove the labeling of marker pen with the help of acetone. For plastic ware do not use acetone for removing marker pen labeling.
6.4.2        Wash the used glassware properly with tap water.
6.4.3        Then scrub the glassware with 0.1% detergent solution or any cleansing agent for regular use.
6.4.4        Special types of precipitate material may require removal with nitric acid, aqua regia or fuming sulphuric acid. These are very corrosive substances and should be used only when required.
6.4.5        If needed dip all the glassware in liquid soap for 2 hours. Remove the glassware from the liquid soap solution. Remove the marker stains using commercial grade acetone.
6.4.6        Brush all the possible areas of glassware.
6.4.7        Rinse all the glassware properly with running tap water.
6.4.8        Again rinse 3 to 4 times with purified water.
6.4.9        Drain the water from glassware.
6.4.10    Dry the glassware in hot air oven at 60oC±5oC.
6.4.11    Remove the glassware using gloves and cool to room temperature.
6.4.12    Now store properly in cupboard. And ready for use.
6.4.13    For microbiology laboratory glassware autoclave the glassware at 121oC, 15lbs pressure for validated cycle time. Plug the mouth of glassware with non-absorbent cotton plug and wrapping the glassware carefully with butter paper. Affix biological indicator if required.
6.4.14    Affix labels having date of sterilization & use before on glassware.
6.4.15    After completion of cleaning affix the “CLEANED” label on the cupboard.
6.4.16    Fill the “Cleaning Equipment Log Book”.
6.5  Special cleaning: (Once in a month/ whenever necessary)
6.5.1        By using hot nitric acid:  Prepare hot nitric acid as specified in SOP BM/QC/SOP070-00.  Wear safety goggles & rubber gloves properly.  Rinse the glassware with hot nitric acid.  Allow it to stand overnight.  Rinse properly with tap water.  Finally rinse with purified water.  Drain the water.  Dry the glassware in hot air oven at 60oC±5oC.  Remove the glassware using gloves and cool to room temperature.                Now store properly in cabinet.
6.5.2        By using chromic acid mixture:  Prepare chromic acid mixture as specified in SOP BM/QC/SOP070-00.  Dip the glassware, once in a month in chromic acid mixture and keep in overnight.  Wear safety goggles & rubber gloves properly.  Remove the glassware carefully.  Rinse the glassware thoroughly for prolonged time with tap water, as glass tends to absorb chromic acid.  Rinse the glassware finally with distilled water.  Dry the glassware in hot air oven at 60oC±5oC.  Remove the glassware using gloves and cool to room temperature.  Now store properly in cabinet.
6.6  Cleaning of specific type of glassware:
6.6.1        Pipette:  Place pipettes tips down, in a cylinder or tall jar containing disinfectant solution immediately after use.  Do not drop them into the cylinder, since this may break or chip the tips and render the pipettes useless for accurate measurements. A pad of cotton or glass wool at the bottom of the cylinder will help to prevent breaking of the tips.  At a convenient time, the pipettes may then be drained and placed in a cylinder or jar of dissolved detergent or, if exceptionally dirty, in a jar of chromic acid cleaning solution.  After soaking of several hours, or overnight, drain the pipettes and run tap water over and through them until all traces of dirt are removed. Soak the pipettes in purified water for at least one hour.  Remove from the purified water, dry outside with a cloth, shake out the water and dry in hot air oven.  After drying, place pipettes in a dust free drawer.
6.6.2        Burettes (with glass stopcock):  Remove the stopcock key and wash the burette with detergent and water.  Rinse with tap water until all the dirt is removed. Then rinse with purified water and dry.  Wash the stopcock key separately. Before the stopcock key is replaced in the burette, lubricate the joint with a small amount of lubricant. Remember those burette stopcock keys are not interchangeable.  Always cover burettes when not in use.
6.6.3        Gooch crucible/ sintered glass funnel:  Fill the gooch crucible of sintered glass funnel with hot nitric acid.  Allow it to stand overnight.  Rinse with raw water.  Apply vacuum and wash the crucible with raw water.  Then wash 3 to 4 times with purified water.  Keep in drier.
6.6.4        Silica crucible:  Fill the silica crucible with nitric acid and heat it over the burner under fuming hood.  Wash with raw water.  Wash with purified water.  Ignite the crucible at 700oC temperature in a muffle furnace.  Cool and keep in respective place.
6.6.5        Petri plates:  Remove agar from the petri plates with a blunt knife.  Collect the agar in a S.S. container and autoclave at 121oC, 15lbs pressure for 30min.  Immediately dispose the medium by burning in the specified place or drain it in ETP.  Dip the plates in a washtub filled with disinfectant solution.  Rinse the plates with tap water and dip them in a washtub containing 2% soap solution or 0.5% Labolene.  Scrub each plate with a brush or scrubber.  Wash each plate thoroughly with tap water to remove soap with purified water.  Finally rinse with purified water. Keep the plates for drying in oven at 60-65oC.  After drying pack 5 to 10 petri dishes in bundle and wrap with cellofen/ butter paper.                Affix indicator if required and autoclave at 121oC, 15lbs pressure for validated cycle time.                Affix labels having date of sterilization & use before.
6.7  Precautions:
6.7.1        After washing with tap water rinsing with purified water must be good enough.
6.7.2        Brush must be selected for the shape and size of the glassware for scrubbing.
6.7.3        Brushes should always be in good condition to avoid any abrasion of the glassware.
6.7.4        It is imperative that all soap detergents and other cleaning fluids be removed from glassware before use. This is especially important with detergents, slight traces of which will interfere with serological and culture reactions.
6.7.5        Always protect clean glassware from dust by use of temporary closures or by placing in a dust free cabinet.
6.7.6        While handling used microbiology laboratory glassware wear disposable latex rubber hand gloves.
6.7.7        All contaminated glassware should be sterilized at 121oC, 15lbs pressure for validated cycle time.
Revision No.
Effective Date


8.1  Not Applicable.
Annexure 1: Cleaning record of Glassware (Cleaning Equipment Log Book).

Annexure: 1
(Cleaning Equipment Log Book)
Cleaning record of Glassware
Cleaned by
Checked by

Expanded Form
Standard operating procedure
Quality control Equipment cleaning
Quality control

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