Researchers in the United States have found some brands of bottled water reportedly contain thousands of loose microscopic particles.
Conducted by Orb Media at the State University of New York, testing on more than 250 bottles revealed a global average of 10.4 plastic particles per litre, Nine News reports.
The 11 brands included in the review also identified contamination with plastics including polypropylene, nylon, and polyethylene terephthalate (PET), although some bottles had no evidence of loose plastic at all.
The study looked at plastic particles in the 100 micron or the 0.10 millimetre range, which is about the size of a human hair.
Plastic bottled water contained an average of 314.6 even smaller particles, with the total global average determined to be 325 per litre.
However, the Australian Beverages Council told Nine News the results of the US study did not accurately represent Australian products.
"The Australasian Bottled Water Institute (ABWI), a division of the Australian Beverages Council, takes the safety of its products very seriously," a spokesperson said in a statement.
"The ABWI Model Code, to which all ABWI Members subscribe, requires bottled and packaged water to be of the highest quality. To this end, Members are audited annually to ensure these high standard are maintained.
"ABWI is aware of a research paper indicating the discovery of polymer particles in bottled water in certain overseas markets. The findings of the research do not relate to Australian products.
"Under ABWI’s Model Code, water products derived from a source other than a public water supply must be rigorously tested by a professionally qualified hydrogeologist. This testing addresses strict conditions related to chemical, physical, microbiological and radiological characteristics of the source."