<Tr> <Td> </Td> <Td> This section needs expansion . You can help by adding to it . (September 2010) </Td> </Tr> <P> Ampoules often have colored rings of paint or enamel around their necks . Color coding of modern ampoules is done during the manufacturing process . A machine paints colored rings on the ampoule shortly after it has been sealed . The rings are made of a substance that is readable by other machines . These color codes identify the substance inside the ampoule so that it does not need to be tested to verify the contents . The machine - readable color codes allow for accurate handling of the substance for the purposes of storage, labeling, and secondary packaging . </P> <P> The dot above the neck identifies the location of a small cut in the glass to help breaking / opening the ampoule . </P>

What are the three differences between an ampule and a vial