Product review (5 stars): It is actually certified by the Water Quality Assoc website!
I have found various products on Amazon that claim 'certifications' that cannot be validated.  BUT - The certification claim they make for these water filters is valid.  I found the product listing at wqa.org. (You really have to hunt to find the link for certified products tested.) It is tested by WQA and certified that the materials meet the ANSI 42 standard.  Filter fits my Whirlpool refrigerator and costs about 30% less than the Whirlpool brand filter.  There is some carbon dust on the connector which you simply wipe off as the instructions mention. The filtered water tastes good.  The product description is very explicit that this is not a Whirlpool brand product but a compatible replacement that costs significantly less. Similar to buying a 3rd party printer ink cartridge for less.  (But this filter does meet some standards which non-brand printer ink cartridges do not.) It seems to me the main reason to use this product is because it costs much less.  The manufacturing process is also supposedly more environmentally friendly.