Parafilm M^® is a moisture-resistant thermoplastic used in research, clinical and industrial laboratories. This laboratory film can be utilized to prevent contamination, evaporation or spills. Parafilm M^® is self-sealing, flexible, odorless, semi-transparent and can stretch and mold to irregular shaped surfaces providing a reliable barrier. Available in an array of sizes, Parafilm M^® can be useful in electron microscopy droplet staining and thin-film grid coating. It can also provide a non-slip surface on trays and shelves for instruments or containers.

Roll Sizes & General Purposes
any size may be used for EM applications

Permeability Characteristics:

• Oxygen (ASTM 1927-98): 150 cc/m² d at 23°C and 50 RH
• Carbon Dioxide (Modulated IR Method): 1200 cc/m² d at 23°C and 0% RH
• Water Vapor (ASTM F1249-01): Flat: 1 g/m² d at 38°C and 90% RH Creased: same as flat
• Note: Because of low water permeability and the insensitivity of this material to moisture vapor, it is unlikely that differences in relative humidity (RH) will make a difference in the oxygen permeability

Effects of Common Reagents:

• Hydrochloric acid conc. (12N) dil. (5N) - no apparent effect in 24 hours
• Sulfuric acid conc. (36N) dil. (5N) - no apparent effect in 24 hours
• Nitric acid conc. (16N) dil. (5N) - no apparent effect in 24 hours
• Sodium hydroxide conc. (22%) - no apparent effect in 24 hours
• Ammonium hydroxide conc. (28% NH3) - no apparent effect in 24 hours
• Potassium permanganate: 5%: no apparent effect except permanent dark brown coloration in 18 hours 0.1%: same as 5% but slightly less color Iodine solution 0.1N: no effect except brown staining in 18 hours
• Salt (NACL) solution 20%: no apparent effect in 24 hours
• Ethyl Alcohol 95%: no apparent effect except some face whitening in 24 hours
• Isopropyl alcohol 99%: no apparent effect in 24 hours
• Not recommended for use with chlorinated, non-polar aliphatic and aromatic solvents
• Film becomes soft and sticky at about 130°F to 150°F (54°C to 66°C)