Sigma-Aldrich PARAFILM M. roll size 2 in. × 250 ft. 1 ea

PARAFILM stretches up to 200% and clings even around irregular shapes and surfaces. The sealing film is free of plasticizers and consists primarily of polyolefins and paraffin waxes. PARAFILM M is resistant up to 48 hours against many polar substances, eg saline solutions, inorganic acids and alkaline solutions.

Protect the integrity of research applications with a tight moisture-barrier that holds a strong seal and doesn′t release from glassware, despite off-gassing
Reduce the risk of tampered data with a covering that is odorless, colorless and semi-transparent
Prevents moisture and volume loss due to material composition and tight seal
Flexible and self-sealing material allows it to cling around irregular shapes and surfaces
Stretches more than 200% of original length
Resistant up to 48 hours against many polar substances such as saline solutions, inorganic acids and alkaline solutions

Permeability
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: 1 g/m² d at 38°C and 90% RH

Effects of Common Reagents
Potassium Permanganate
5%: No apparent effect except permanent dark brown coloration in 18 hours
0.1%: Same as 5% except slightly less color
Iodine solution (0.1N)
No effect except staining brown in 18 hours
Ethyl Alcohol (95%)
No apparent effect except some face whitening in 24 hours
No apparent effect in 24 hours:
Hydrochloric Acid conc. (12N) dil. (5N)
Sulphuric Acid conc. (36N) dil. (5N)
Nitric Acid conc. (16N) dil. (5N)
Sodium Hydroxide conc. (22%)
Ammonium Hydroxide conc. (28% NH₃)
Salt (NaCl) solution (20%)
Isopropyl Alcohol (99%)

Not recommended for use with chlorinated, non-polar aliphatic and aromatic solvents
Film becomes soft and sticky at about 130° to 150°F (54° to 66°C)

Parafilm is a registered trademark of Bemis Company, Inc.