Guide to Materials and Sterilization > Thermoplastic Sterilization Chart


THERMOPLASTIC: GAMMA STERILIZATION

Guide to Ratings in Sterilization Chart

Note: “Damage” refers to significant changes that affect the physical properties; other effects like discoloration may occur at lower doses.

  • Excellent: Doses of more than 100 Mrads may not cause significant damage.
  • Good: Doses in range of 20 to 100 Mrads may cause significant damage.
  • Fair: Doses in range of 5 to 20 Mrads may cause significant damage.
  • Poor: Significant damage may occur at doses of 2 Mrads or less.

Gamma Sterilization of Thermoplastics

Information is for reference only. The suitability of a material for your project must be determined as part of the product development process.

Material Stability Comments
Acrylonitrile/Butadiene/Styrene (ABS) Excellent
Aromatic Polyesters (PET, PETG) Excellent No discoloration.
Cellulosics Fair Esters better than cellulose acetate.
  • Esters and Ethers
 Fair
  • Cellulose Acetate
 Fair
Fluoropolymers Poor TFE and PCTFE are significantly damaged at low doses.
  • Tetrafluoroethylene (TFE)
 Poor
  • Polyvinyl fluoride
 Good Tends to cross link.
  • Polyvinylidene fluoride
 Good Tends to cross link.
  • Ethylene-Tetrafluoroethylene (ETFE)
 Good Tends to cross link.
  • Fluorinated ethylene propylene (FEP)
 Fair OK for some applications
Polyacetals (Deirin, Celcon) Poor Irradiation causes severe embrittlement, discoloration, and cracking over time.
Polyacrylics Fair Yellow discoloration tends to fade with time. Stabilized and tinted materials available.
  • Polymethylmethacrylate
 Fair
  • Polyacrylonitrile
 Fair
  • Polyacrylate
 Fair
  • Polyhydroxacrylate
 Fair
  • Polycyanoacrylate
 Fair
Polyallomers Good Copolymer of polyethylene and polypropylene reduces oxidation embrittlement of polypropylene.
Polyamides (Nylons)
  • Alphatic
 Good Slight discoloration possible. Tends to cross link increasing tensile strength.
  • Aromatic
 Excellent
Polycarbonate Excellent Yellows slightly. Mechanical properties not much affected. Tints stabilizers available.
Polyethylene Excellent Cross links, tensile strength increases, and modulus of elasticity decreases.
Poly (ethylene-acrylate) Good
Polyimides Excellent Doses exceeding 1000 Mrads are OK.
Polymethylpentene Good
Polyphenylene Sulfide Excellent Doses exceeding 5000 Mrads are OK.
Polypropylene Good to Poor Stabilization required to prevent embrittlement. Exercise caution because effects may increase with time – months after irradiation.
Polystyrene Excellent Slight yellow discoloration possible.
Polysulfone Excellent Natural material is yellow.
Polyvinyl formal Good Less stable than PVC.
Polyvinylbutyral Good Less stable than PVC.
Polyvinylchloride (PVC) Good Can discolor but stabilizers available to prevent yellowing.
Polyvinylidene Chloride Good Less stable than PVC.
Styrene/Acrylonitrile (SAN) Excellent Less stable than styrene alone.
Allyl digylcol carbonate (polyester) Excellent Maintains excellent optical properties.
Epoxies Excellent Aromatic curing agents are recommended.
Phenolics Excellent Mineral fillers increase stability
Polyesters Excellent The use of mineral fillers or glass fibers further increases stability.
Polyurethanes Excellent Discoloration is normal.