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What are the risks from Vaseline / Uranium glass ? Uranium oxides have been commonly used as colourants in glassware and ceramics since the 19th century . The addition of uranium to glass produces a yellow or green colour and under ultraviolet light the uranium fluoresces , causing the glass to glow with a bright green colour . This type of glass is often referred to as Vaseline glass . There is no production of Vaseline glass in the UK now , though there are many collectors who obtain pieces from the UK antiques market or import from abroad .
The main emission from Vaseline glass is beta radiation , with negligible gamma dose rate close to the surface . Handling of the glass could therefore give rise to a skin dose , but there will be negligible exposure from viewing a display of glass items . A study of a collection of items made from Vaseline glass found that beta dose rates at the surface of a range of items were mostly very low ( 1-15 µ Sv / h ), though a few items gave higher values , up to around 100 µ Sv / h . Assuming a surface dose rate of 15 µ Sv / h , if a collector spent the equivalent of one day a year ( 7 h / y ) handling this glass , the annual skin dose to the hands would be about 100 μSv . This equates to an effective dose of around 1 µ Sv , which is below the recommended constraint of 3 µ Sv recommended by NRPB ( now UKHSA ) in 1992 , for consumer products that are not related to safety .
The items of jewellery studied typically gave higher surface dose rates , and it is estimated that wearing such a necklace for a few hours each week could lead to an effective dose approaching 3 µ Sv . However , estimated doses are below the skin dose limit of 50
2 mSv / y averaged over 1 cm recommended for members of the public , and resulting estimates of effective dose are at a level generally considered to be trivial .
Conservative estimates of the annual dose from regular use of items of Vaseline glass used for drinking suggest doses would be much lower than the level regarded as trivial .
For more information see S J Watson and J S Hughes 2010 J . Radiol . Prot . 30 ( 3 ) 535
Vaseline glass marbles : The small marbles are approximately 12.5mm in diameter and the large one 25mm . They were photographed using a 100mm macro lens on a dark surface illuminated solely by a LED ultraviolet torch directed from in front and above . ( ISO 500 , f16 , 1 / 8 second ).
Photo acknowledgement John Liddle
14 Radiation Protection Today www . srp-rpt . uk