Section 465.340  Laboratory Glassware, Plastic Ware and Metal Utensils

a)         Except for disposable plastic ware, items shall be resistant to effects of corrosion, high temperature, and vigorous cleaning operations.  Metal utensils made of stainless steel are preferred.  Plastic items shall be of inert, non-toxic material and shall retain accurate graduations or calibration marks after repeated autoclaving.  Glassware which is used for purposes that may subject it to damage from heat or chemicals shall be of borosilicate glass. All glassware shall be free of chips, cracks, or excessive etching.  All volumetric glassware shall be Class A, denoting that it meets federal specifications and is certified by the manufacturer as meeting the standards established by the American Society for Testing and Materials (ASTM).

b)         Graduated cylinders for measurement of sample volumes shall have a tolerance of 2.5% or less.  Precalibrated sample containers shall have clearly marked volumes of 2.5% tolerance.  The calibration of each precalibrated sample container shall be checked before first use by measuring the volume of 10 calibrated containers per lot.

c)         Media preparation utensils shall be of borosilicate glass or stainless steel, and shall be clean and free from foreign residues or dried medium.

d)         Pipets and pipettors shall meet the specifications set forth in "Standard Methods for the Examination of Water and Wastewater." Containers for glass pipets shall be of either stainless steel or aluminum.  Opened packages of sterile disposable pipets shall be securely resealed between uses. A pipet aid shall be used when using pipets; mouth pipetting is prohibited.

e)         Culture dishes shall be sterile and shall be of the tight or loose-lid plastic, or loose-lid glass, type.  In addition, culture dishes shall be of 100 mm x 15 mm, 50mm x 12 mm, or 60 mm x 15 mm size; and shall be clear, flat bottomed, and free from bubbles or scratches or both.  Containers for culture dishes shall be of aluminum or stainless steel; or culture dishes shall be wrapped in heavy aluminum foil or char-resistant paper.  Open packages of sterile disposable culture dishes shall be securely resealed between uses. Loose-lid dishes shall be incubated in a tight-fitting container to prevent dehydration of membrane filter and medium.

f)          Culture tubes shall be of borosilicate glass or other corrosion resistant glass, and shall be of sufficient size to contain culture medium, as well as the sample portions employed, without being more than three-fourths full. Culture tube closures shall be loose-fitting stainless steel, or plastic caps, or aluminum caps, or plastic screw caps with non-toxic liners.

g)         Dilution bottles shall be of borosilicate glass or other corrosion resistant glass or autoclavable plastic and shall be free of chips and cracks at the lip.  A graduation level shall be distinctly marked on the side of dilution bottles at 99 ml.  Dilution bottle closures shall be plastic screw caps with leakproof liners and shall not produce toxic substances during the sterilization process.

h)         Sample bottles shall be sterile, of plastic or hard glass, wide mouthed, and of at least 120 ml capacity.  Sample bottle closures shall be glass stoppers or screw caps (metal or plastic), capable of withstanding repeated sterilization, with leakproof liners, and shall not produce toxic substances during the sterilization process.  Glass-stoppered bottle closures shall be covered with aluminum foil or char-resistant paper for sterilization.  Metal caps with exposed bare metal on the inside shall not be used.  Presterilized bags, with or without a dechlorinating reagent, may be used.