The Small Gram Quantity (SGQ) concept is based on the understanding that small amounts of hazardous materials, in this case radioactive materials, are significantly less hazardous than large amounts of the same materials. The essential functional requirements for RAM packaging are containment of the material, ensuring sub-criticality, and ensuring that the radiation hazard of the package, as represented by the radiation dose for the package, is within the regulatory limits. Knowledge of the composition of the material being shipped is also required. By placing the contents in a containment vessel which is helium leaktight, and limiting the mass so that subcriticality is ensured, the first two requirements are readily met. Some materials emit sufficiently strong photon radiation that a small amount of material can yield a large dose rate. Foreknowledge of the dose rate which will be present for a proposed content is a challenging issue for the SGQ approach. Issues associated with certification for several cases of contents which fall within the SGQ envelop are discussed.
Toxicity and chemical transformation of silver nanoparticles in A549 lung cells: dose-rate-dependent genotoxic impact