Gamma Clay

Malleable, non drying, gamma shield


Gamma Putty is a malleable gamma shielding clay that contains no lead. It is a lower density, more economical material than our bismuth-based putty. It contains iron powder that is uniformly distributed throughout the LDPE binder material to insure there are no gamma streaming paths. The additive is elemental iron, 70% by weight, and the material will not dry out to form a powder. It is supplied in chunks that are readily pliable by hand and holds its shape after placement.

Medical Application

GammaClay can be used to protect patients during orthovoltage x-ray treatments. In this type of treatment, x-rays of several hundred kvp are used to treat localized skin cancers and similar lesions. It is desirable to protect the surface surrounding skin areas from radiation. In the past, this was accomplished by cutting lead sheets or casting molten metals into special moulds. EnviroClay is readily pliable, yet has enough consistency to hold it’s shape after placement. It requires no special tools or techniques to produce patient shields. This material permits accurate, reproducible technique for obtaining small openings in shields moulded to fit patients.

  • It is non-hardening and it will not dry out to form a powder
  • Reusable and lead-free
  • Provided in 4.5 kg cans

Typical applications include temporary gamma shielding during reactor maintenance, shielding for cable tray penetrations, and industrial radiographic film masking. Disposable gloves are recommended when handling as the putty is quite sticky

Composition Data Important Properties
Hydrogen atom density / cm3 3.3 x 10²²
Natural isotope distribution 99.98% ¹H
Bismuth atom density / cm3 9.9_10²¹
Weight percent bismuth 90%
Total Density 3.8 g/cm³ (238 lbs/ft³)
Radiation Properties
Macroscopic Thermal Neutron Cross Section cm-1: 0.01 cm⁻¹
Lead Equivalent Thickness (inch): 0.39
Attenuation Factors for 1 inch
200 KeV 1.9 x 10⁴
500 KeV 4.7
1.0 MeV 2
Attenuation Factors for 2 inch
Ir-192 30
Cs-137 8.4
Co-60 3
Gamma resistance 5_10⁸ RAD
Neutron Resistance 2.5_10¹⁷ n/cm²
Physical Properties
Machinability: poor
State Putty
Colour Gray
Odour No significant odour
Thermal Properties
Recommended Temperature Limit: 45℃ (110℉)
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