"HP does not agree with its conclusion [nor] some of the bold claims the authors have made recently in press reports," he said in a statement.
He explained that ultrafine particle testing is "a very new scientific discipline" and added that "there are no indications" of laser printing systems posing special health risks.
Other household and office products may even emit similar particles, which are actually harmless, he added.
"Many experts believe that many of the UFPs found in common household and office products are not discrete solid particles, but may be condensation products or small droplets created during thermal processes," said Mr Tran.
The company also provides a recycling service for printer cartridges and other computer equipment.