This one is not an affiliate post. I make zero dollars if you buy from eBac Water. I am writing it up because bacteriostatic water is the one supply item that touches almost every peptide research setup, and I have not seen anyone actually check a vendor's COA on it the way I check one on a peptide.
Why bacteriostatic water gets its own review
Bacteriostatic water is sterile water with 0.9% benzyl alcohol added as a preservative, the same standard formulation used across the research supply market. It sounds like a commodity, which is exactly why people stop paying attention to it. Contaminated or mislabeled diluent does not just fail on its own. It compromises whatever research sample it touches. A peptide vendor with a spotless COA does not help you if the water you are combining it with was never actually tested.
The order
I placed an order with eBac Water myself. I got an order confirmation, the order shipped the same day, and it arrived in 3 days. Nothing dramatic to report, which in a category where slow or silent order handling is a common complaint, is itself worth noting.
Verifying the COA
eBac publishes a COA per batch through Chromate, a third-party lab, rather than an in-house test sheet. My vial's lot number matched the batch on the COA (EB61901) Verified COA, and the certificate includes the actual HPLC chromatogram, not just a results table typed up after the fact.
Here is what the COA actually covers, and why each line matters for research use specifically:
- Identity (RP-HPLC with UV detection). Confirms the solution is actually benzyl alcohol and not something else entirely. This is the test that catches a mislabeled or substituted product before it ever gets near your research.
- Quantity, 0.9% specification, 0.921% result. Confirms the preservative is present at the labeled concentration, not just "some amount." Consistent concentration is what makes a research diluent usable batch to batch.
- Sterility (USP <1223> BacT/ALERT), Pass. Confirms no microbial contamination in the vial. This is the single biggest way a diluent can quietly wreck an otherwise clean research sample.
- Endotoxins (kinetic chromogenic LAL assay), under 0.25 EU/mL against a 0.5 EU/mL limit. Endotoxin contamination is invisible and does not show up as cloudiness or smell. A real LAL assay result, well under spec here, is the only way to actually know it is not present.
- pH, 4.5 to 7.0 specification, 6.253 result. Confirms the solution is within the expected formulation range rather than drifting from improper storage or a bad production run.
Chromate, the lab that ran these tests, presents itself as an independent third party rather than an in-house eBac lab, which is the right structure. I will note honestly that Chromate's own site does not list a specific accreditation body (no ISO certification number or similar), so treat "independent" here as "a separate company," not as a guarantee of accreditation. The COA includes a public verification code (COA #35348, access code EBAC444D2MUF) through chromate.org/verify if you want to check it yourself.
Pricing
eBac's pricing scales with pack size, standard retail down to a 25-vial case:
| Pack Size | Price per Vial | Savings |
|---|---|---|
| 1 vial | $11.00 | Standard |
| 3 vials | $9.67 | 12% |
| 5 vials | $9.00 | 18% |
| 10 vials | $7.50 | 32% |
| 25 vials | $6.76 | 39% |
The $6.76 per vial figure is the 25-vial case price ($169.00 total), not a special wholesale rate. eBac also lists a separate contact-for-quote tier for 200 or more vials or recurring bulk supply, with no published pricing for that tier.
(This is not an affiliate link. I do not have a partnership or financial relationship with eBac Water, and nothing about this recommendation changes if you buy from them or not.)
What I'd still check before you order
- Confirm the batch number yourself. Check the lot number on your own vial against eBac's published COA when it arrives, the same way I checked mine.
- Match the pack size to what you actually need. The per-vial price drops fast between the 1-vial and 25-vial options, so buying in the smallest useful bulk size is where the real savings are.
- Re-check this post's freshness. Lot numbers and COAs change with each production batch. If it has been a while since the date at the top of this post, verify the current batch's COA rather than assuming it matches what I checked.
Papa's take
I do not make anything from this recommendation, which is exactly why I am comfortable being direct about it: this is the bacteriostatic water I currently use, the COA held up when I checked it against the physical vial, and the order itself was uneventful in the best way. Everything discussed here is for research use only, not for human consumption.