Using Blue HDPE Containers

George received some low trace metals material that was delivered in a blue HDPE container. Eventually, he planned to transfer it to a LDPE container. George wanted to know what was considered "short-term storage" in HDPE and what specific contaminates the blue coloring might contain.

	RE: Using Blue HDPE Containers Dear George,      All of the blue pigments I am familiar with contain copper combined with a combination of an organic ligand and maybe an inorganic ligand to modify the shade of blue. A point of interest -- there were over 700 different shades of blue available during the time of the American Revoultion.      I do not have a definition for short-term exposure unless I have an understanding of the leaching curve of the contaminant of concern. If your sample is non-acidic and relatively inert, it is unlikely that a blue pigment will readily leach. Pigments in general are chemically unreactive. Therefore, in this case a short exposure could be as long as a day or more. If the sample is polar (not wetting the container) and neither caustic or acidic (pH between 4 and 10), you should be okay. However, you may want to encourage your co-workers to consult with you before they collect a sample. It is to their benefit as well as to yours that they consult with you before starting a project requiring trace analysis. Please contact me with any other concerns.     Paul R. Gaines, Ph.D. Serving you in chemistry