People buy it, but then this sometimes happens:
vendor BAC + reta = cloudy reta
Other concerns are endos, sterility, pH, and BAC content. Most tests of vendor water are only for the last two.
To my knowledge, the best non-Hospira source of BAC water regarding testing of all four:
Ocean Pharmaceutical - Pharmaceutical Distributor in Vadodara
High-quality pharmaceutical products from Ocean Pharmaceutical, Vadodara's leading firm, committed to excellence since 2016.
oceanpharmaceutical.com
But that's just a small company in India. And each batch needs to be tested. (Hospira is also produced in India, but at much better facilities and not for IndiaMart.)
Filtering after recon would help with sterility concerns, but that still leaves endo concerns.