Nalco 3688 Site

Nalco 3688 is viscous. For accurate metering, dilute it with:

Do not dilute with water. This will destroy the product's efficacy. nalco 3688

While the exact formula is a trade secret, Material Safety Data Sheets (MSDS/SDS) and technical literature indicate that Nalco 3688 contains: Nalco 3688 is viscous

Importantly, Nalco 3688 does not contain chromate (hexavalent chromium), making it environmentally preferable compared to older, more toxic treatments. However, it does contain phosphorus, which means discharge into natural water bodies may be regulated. Do not dilute with water

Nalco 3688 is a proprietary, multi-functional liquid treatment chemical manufactured by Ecolab’s Nalco Water division. It is primarily formulated for use in open recirculating cooling water systems, though it finds limited application in closed loops and once-through systems.

The chemical is best described as a stabilized phosphate-based corrosion inhibitor blended with proprietary polymers for scale control. Unlike simple orthophosphate treatments, Nalco 3688 is designed to provide a dual-action mechanism:

It is typically supplied as a clear to amber liquid with a neutral to slightly acidic pH. The product is part of Nalco’s legacy “3000 series” of cooling water treatments, known for their reliability in moderate to large industrial systems.