THE GILBERT U-238 ATOMIC ENERGY LAB. The dangerous children's science kit.

The Gilbert U-238 Atomic Energy Lab was a science kit for children released in the United States in 1950 by the A. C. Gilbert Company. It is famous for being one of the few toys in history that included actual radioactive materials for conducting nuclear physics experiments at home.

The kit.

The Gilbert U-238 Atomic Energy Laboratory consisted of a complete scientific setup with four types of uranium ore (autunite, torbernite, uraninite, and carnotite), as well as instruments such as a spinthariscope, an electroscope, and a Geiger-Müller counter for measuring radiation. It was manufactured by the A. C. Gilbert Company, founded by Alfred Carlton Gilbert, an American Olympic athlete and inventor.

The set included four low-intensity radioactive sources: alpha emitters (polonium-210), beta emitters (ruthenium-106 and lead-210), and gamma emitters (zinc-65). Unlike chemistry sets of the time, this kit did not include chemical reagents or fuels; instead, it focused exclusively on the observation and measurement of nuclear phenomena.

The kit included the "Gilbert Atomic Energy Manual," a book of about 60 pages featuring more than 150 experiments. It was written by Dr. Ralph Eugene Lapp, a nuclear physicist who had participated in the Manhattan Project. It also included the educational comic book "Learn How Dagwood Split the Atom" and the official guide "Prospecting for Uranium."

Although the promotional material assured parents that the substances were safe, the manual warned that radiation sources in sealed vials should not be handled directly, as they could crumble and scatter radioactive material into the environment.

Commercialization.

The kit was sold for $49.50 USD in 1950, which is equivalent to more than $600 USD today. This made it a luxury item that was unaffordable for the vast majority of families, which is why it remained on the market only from 1950 to 1951, selling fewer than 5,000 units in total.

Market withdrawal.

Although popular belief holds that it was banned because it posed an extreme health hazard, its withdrawal was due to commercial factors: the high price and complexity of the kit, which was designed for advanced technical students rather than the typical child audience.

Although the sources were of low intensity and the Oak Ridge laboratories certified their safety at the time, under modern radiation protection standards it is not considered appropriate to place free radionuclides within children's reach. For this reason, the press has retrospectively described it as one of the “most dangerous toys in history.”

Today, it is an extremely rare collector's item. Incomplete kits typically sell at auction for around $2,500 USD, while complete sets in excellent condition can fetch over $10,000 USD.