CitriSurf® 2325

Technical Data:


CitriSurf 2325 is a high quality passivation treatment blend of chemicals formulated for cleaning, rust removal and passivation of stainless steel products. CitriSurf 2325 is specifically designed to provide low cost and efficient removal of contaminants and all rust and free iron from the surface of stainless steel, providing the highest chrome oxide levels possible.
[PDF] Download this page

Physical Properties:

Specific Gravity 1.07
Approx. wt. /gallon 9.5 lb/gal
Viscosity 3 cps
Form Liquid
Chemical Composition Citric acid, water, proprietary ingredients
Operating Temperature Room temp or higher (120-160°F preferred)
Flash Point None
Water solubility Complete
Normal working concentration 20-33% by volume in water
pH at working concentration approx. 1.6


5 gallon or 55 gallon plastic containers. Larger sizes available upon request.

Application Procedure:

To assure best results and help extend the life of the bath, the parts to be passivated may be cleaned with an appropriate cleaning solution prior to passivation treatment with CitriSurf solution, especially when heavy grease and oils or residue of other materials are present.

Stellar SolutionsAll equipment, mixers, tanks and pumps should be clean and dry prior to mixing of CitriSurf passivation treatment solution. CitriSurf 2325 should be mixed with clean water (purified water if desired) at a ratio of 1 part of CitriSurf 2325 with 3 to 5 parts of water by volume to fill the tank used so as to fill the clean in place (CIP) loop or adequately cover all parts to be treated. Polypropylene, stainless steel, or equivalents should be used for construction of all tanks and devices used in the CitriSurf solution. For parts, agitation of the passivation treatment solution in the tank is strongly recommended to attain optimum results. Optimum results can be obtained with many parts by using CitriSurf in an ultrasonic tank.

Heat the solution for optimum performance. 120-160°F is typical. Room temperature is often adequate with increased flow or immersion time. Teflon coated (or equivalent), stainless steel or titanium heating devices are recommended.

Flush the solution through the CIP loop or completely immerse the parts to be passivated in the solution for a period sufficient to remove all free iron and contaminants from the surface. CIP operations are typically run for 30-60 minutes. For parts this is typically 15-30 minutes, depending on temperature, grade of stainless steel, hardness, use of ultrasonics, and the condition of the surface of the parts. Your tests should indicate the best combination of bath parameters for the products you manufacture. Difficult rust or corrosion must be tested to determine the exact best conditions for removal. If heavy rust needs to be removed, Scotch Brite™ or other non iron containing abrasive may be helpful.

Rinse the CIP loop or parts thoroughly with clean water. Flowing water is optimum. Purified water may be used to prevent water spotting. Dry completely in air immediately. Drying of parts can be accelerated by use of a hot air oven or other drying medium to attain a highly passive surface.

Notes on Use:

Although CitriSurf 2325 will not harm most metal parts or surfaces, and will enhance the brightness when used as directed, test a single part or small area before full application. The use of this product on sensitive grades of stainless steel may result in discoloration or etching of the metal.

Although very safe in normal use, CitriSurf 2325 is a citric acid based material, and as such it may cause irritation to exposed surfaces of the body. See Safety Data Sheet before using this material.

For large items, on-site, or spot treatment applications, ready to use versions CitriSurf 77 Plus and CitriSurf 2310 are available.


Replenish the bath with CitriSurf and water as appropriate to compensate for dragout, evaporation, and acid consumption. The pH of the CitriSurf 2325 bath should be held to within +0.1 of its initial value for normal operation.


Dispose of according to all federal, state and local regulations.


CitriSurf 2325 should be stored at temperatures between 50°F and 120°F in 316 stainless steel or approved plastic containers (polyethylene or polypropylene). (If accidentally frozen, thawing will return product to normal.)

Technical Services:

For technical assistance, please contact Stellar Solutions at (847) 854-2800.


When used correctly, CitriSurf 2325 meets the requirements of the ASTM A967, ASTM A380, ASTM B600, and AMS 2700 standards.

Testing of your products with CitriSurf before using in production is recommended. Every product and production facility is different, and requires testing to ensure that CitriSurf is compatible with the particular situation. No warranty is implied, or may be given in writing or verbally without the written permission of Stellar Solutions, Inc.

Nonfood Compounds
Program Listed A3