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Cleaning and Packing Procedures for Laboratory Glassware 

1. Purpose

These procedures outline the standard methods for cleaning laboratory glassware and packing broken scientific glass for safe shipping. Adhering to these guidelines ensures the safety of personnel and the integrity of glassware during handling and transit. 

2. Cleaning of Laboratory Glassware

Proper cleaning ensures the safety of glassblowers and enhances repair quality. All residues, stickers, tape, and adhesives (except brand decals) must be removed. 

2.1 Scope 

Applies to all personnel responsible for preparing glassware for repair. 

2.2 Personal Protective Equipment (PPE) 

  • Safety goggles 

  • Lab coat 

  • Chemical-resistant gloves 

2.3 Materials Required 

  • Acetone, Hexane, or Heptane 

  • Isopropyl alcohol (IPA) or Ethanol 

  • Decahydronaphthalene (for stubborn grease removal) 

  • Mild laboratory detergent (e.g., Alconox, Liquinox) 

  • Distilled or deionized water 

  • Soft brush or sponge (non-abrasive) 

  • Lint-free wipes or paper towels 

2.4 Cleaning Procedure 

2.4.1 Removing Silicone Grease 

  1. Initial Wipe: Remove as much grease as possible using a lint-free wipe or paper towel. 

  2. Solvent Rinse: Apply hexane or heptane to a clean cloth and thoroughly clean affected areas. 

  3. Alcohol Rinse: Follow with an isopropyl alcohol or ethanol rinse to remove solvent residue. 

2.4.2 Stubborn Grease Removal 

  1. Decahydronaphthalene Soak: Soak glassware in warm decahydronaphthalene for 2 hours, then rinse with acetone followed by water. 

  2. Acetone Soak: Alternatively, soak glassware in acetone to dissolve silicone grease before proceeding to routine cleaning. 

2.4.3 Routine Cleaning After Grease Removal 

  1. Detergent Wash: Soak glassware in warm water with mild lab detergent for 10–15 minutes. 

  2. Scrubbing: Use a soft brush or sponge to remove remaining residues. 

  3. Rinsing: Rinse at least three times with tap water, followed by two rinses with distilled or deionized water. 

  4. Drying: Place glassware on a drying rack in an inverted position to air dry. 

2.5 Consequences of Not Removing Silicone Grease 

If silicone grease is not removed from glassware and is heated in an annealing oven at 1000°F (538°C), several things can happen: 

  1. Decomposition and Burning – Silicone grease is composed of polysiloxanes and other additives. At high temperatures, it decomposes, producing silica (SiOâ‚‚), carbon residues, and volatile organic compounds. The grease can leave behind difficult-to-remove residues that may affect future experiments or applications. 

  2. Carbonization and Contamination – The organic components of the grease will likely char and form carbon deposits, which can stick to the glass surface, making cleaning extremely difficult. This contamination can interfere with precise laboratory work. 

  3. Fuming and Toxic Byproducts – Some silicone grease contains volatile additives that could release toxic fumes when exposed to extreme heat. This may pose a safety risk in poorly ventilated environments. 

  4. Potential Interaction with Glass – Depending on the composition of the grease, some elements may chemically interact with the glass, leading to surface etching, weakening, or discoloration. 

Best Practice: Before annealing glassware, always thoroughly remove silicone grease using an appropriate solvent (such as hexane, acetone, or isopropanol) followed by a proper cleaning procedure. This prevents contamination and preserves the integrity of the glassware. 

2.6 Final Inspection & Shipping Preparation 

  • Acetone, Hexane, or Heptane 

  • Isopropyl alcohol (IPA) or Ethanol 

  • Decahydronaphthalene (for stubborn grease removal) 

  • Mild laboratory detergent (e.g., Alconox, Liquinox) 

  • Distilled or deionized water 

  • Soft brush or sponge (non-abrasive) 

  • Lint-free wipes or paper towels 

3. Packing Broken Scientific Glass for Shipping 

3.1 Safety First 

  • Wear protective gloves and safety goggles to avoid injury from sharp edges. 

  • Use a clean, flat workspace to prevent further breakage. 

3.2 Materials Required 

  • Sturdy cardboard box 

  • Bubble wrap or foam padding 

  • Packing peanuts or crumpled paper 

  • Heavy-duty packing tape 

  • Labels (e.g., "Fragile," "Handle with Care") 

3.3 Packing Procedure 

  • Sturdy cardboard box 

  • Bubble wrap or foam padding 

  • Packing peanuts or crumpled paper 

  • Heavy-duty packing tape 

  • Labels (e.g., "Fragile," "Handle with Care") 

3.3.1 Prepare the Glass 

  • Carefully collect all broken pieces, regardless of size or condition. 

3.3.2 Wrap Each Piece 

  1. Individually wrap each piece of glass in bubble wrap or foam padding and secure with tape. 

  2. Double-wrap larger pieces for extra protection. 

3.3.3 Box Preparation 

  1. Line the bottom of the box with a layer of packing peanuts or crumpled paper. 

  2. Place wrapped glass pieces in the box, ensuring they do not touch each other or the box's sides. 

  3. Whenever possible, we recommend placing the box with the glass in it inside a larger box with 1 to 2 inches of packing material between them. This extra cushioning helps protect your items from potential damage caused by unexpected forces during shipping and handling. 

3.3.4 Fill and Seal the Box 

  1. Fill gaps with packing material to prevent movement. 

  2. Add a final cushioning layer on top before sealing the box with heavy-duty tape. 

  3. Shake the box gently to ensure there is no movement or glass on glass noises; add more packing material if necessary. 

3.3.5 Labeling and Shipping 

  • Clearly label the box with "Fragile" and "Handle with Care" stickers. 

  • Include additional labels such as "Broken Glass" or "Scientific Equipment." 

  • Inform the shipping provider about the contents for proper handling. 

By following these steps, personnel can ensure the safe handling, cleaning, and shipping of laboratory glassware. If further assistance is needed, consult the lab supervisor or shipping coordinator. 

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