Ultimately, if you can find out what it is made of, that would be a good thing. I did not see the construction material listed on your link. Most plastics are going to be fine, but you should wash the container out to get rid of any releasers they might have used when the thing was injection mold formed. I usually use some salt mix with enough water added to make it a paste, then scrub the container with that, then rinse.
Another thing to be aware of is that sometimes in these containers there are pin holes in the bottom to let air out when you put the top on it, as they are not intended for liquid storage to begin with.
Finally, you may want to test fill it with water from a garden hose to be sure it will not crack or bow out too much from being filled with liquid, as this is not the purpose of the holder. Some plastic bins that hold towels fine are not suited to liquids and will crack from being filled with water.
EDIT:
Forgot to add this: I use something similar, but a good bit larger (30 gallons) as my ATO water holder, and it had one of those vent holes I mentioned above, so I took a soldering iron and heated some of the plastic around the hole, and effectively plugged it. No leaks after a year, but if I fill it up too high, the thing really bows out, so I have to keep it about 3/4 full or less. Nice thing yours being clear, as it provides at-a-glance info about how full/empty it is.