Dura®, Durachrome®, are trade names of Plating Resources, Inc. Copyright and all other World Rights Reserved, 1990, 1995, 2014.





Cancel ST-45 is a concentrated liquid fume suppressant for chrome plating baths. It lowers the surface tension of these baths for compliance with both worker safety and air discharge regulations. It is a medium-foaming type of fume suppressant.

Cancel ST-45 is a permanent fume suppressant that is not oxidized by the chrome bath.

Cancel ST-45 is capable of reducing the chrome mist by over 99%. When properly used it can exceed the OSHA PEL Action Level of 2.5 ug of CR(VI) and the EPA air quality standard of 0.015 mg/dscm.

Cancel ST-45 is the lowest cost permanent product on the market.
Compliance possible without expensive ventilation system changes.
Less mesh pad plugging, cleaner hoods, tank rims, bussing & fixtures.
Lower surface tension for reduced drag-out and better rinsing–recovery.
Does not break down to cause pitting or coatings on the anodes.
Very effective in controlling Cr(VI) misting, over 99% effective.
Does not contain any PFOS chemicals.

Additions & Maintenance:
The initial addition shown is for baths without any fume suppressant present. This amount will be lower if converting a bath.

Initial Addition (% by volume): 1.3% for 45 dynes
1.6% for 35 dynes
Maintenance Additions, (10,000 amp. hours): 300 mls. (10.0 fl. ozs)

Use the above amounts as a starting point. Some baths with a lower initial dynes will require more than what is indicated. It’s best to go slow and make multiple additions.

Bath Additions:
Always agitate the Cancel ST-45 before measuring as some settling may occur. It is best to dilute the product (4-5 times) with water before adding to the bath. Spread the addition evenly across the baths surface. Regular testing and small but frequent maintenance additions are recommended to maintain the desired surface tension, as per the regulations. The addition of Cancel ST-45 will cause a temporary foam blanket to form. This foam generally dissipates in 1-3 days and is not an indication that the surface tension has necessarily increased.

Surface Tension:
Most chrome baths have a surface tension between 75 and 90 dynes/cm., depending on the chromic acid level and the amount of trivalent, iron and copper present. Cancel ST-45 can lower this to below 20 dynes/cm, but most operations will want to maintain a surface tension of around 35 dynes/cm. Surface tension can be controlled by either a stalagmometer or a tensiometer, with additions made per the chart. Irrespective of a foam blanket, a low surface tension reduces the chrome misting significantly by preventing large gas bubble formation.

The conversion addition is based on the desired surface tension, as per the chart. It is best to make these additions in small equal steps until the desired surface tension or foam thickness is obtained. Cancel ST-45 is compatible with all other types.

Foam Blanket Height:
A foam blanket along with low surface tension provides the best control of chrome misting. Thick foam blankets, however, should not be used in operations with high solution levels where the mist can overflow the tank or be drawn into the hood, where hydrogen explosions are possible (due to low buss bar height), where bath cooling is a problem, if trivalent & metallic impurities are high, or for thick hard chrome deposits. In these cases the use of a non foam fume suppressant FS-900 is best.

Other Applications:
Cancel ST-45 can also be used in plastic etch baths, and in chrome or sulfuric anodizing tanks to effectively control emissions.

This process uses industrial strength chemicals which must be handled carefully and in accordance with the directives provided in the individual MSDS forms. Read and understand the MSDS on all of these chemicals before handling or using. Ensure that all regulatory standards are followed and limit personal exposure as required for Cr(VI) and other chemicals by OSHA.

Avoid personal contact with these chemicals, avoid splashing and avoid breathing any fumes released during operation. Do not inhale any dust, mist or vapors from these chemicals. Do not allow these products to contact the skin or eyes. In case of contact, flush immediately with large amounts of fresh water and seek immediate medical attention. Wear protective clothing such as aprons, gloves, face masks and respirators. Be sure that adequate eyewashes and emergency showers are available nearby before handling or using any of these chemicals. Designated work clothing should be worn while using these chemicals and the worker(s) should thoroughly shower and change into fresh-clean street clothing before going home. Decontaminate all work clothing before reuse. The user is responsible for providing adequate work clothing, personal protection, limiting personal exposure and providing any required clean-up, decontamination as well as any needed medical attention.

Disclaimer & Non-Warranty:
This information is, to the best of our knowledge, true and accurate. All recommendations are, however, made without guarantee or warranty and Plating Resources, Inc. specifically disclaims any and all liability arising from the use of these products or the information contained herein. All factors relating to compliance with OSHA worker safety and EPA environmental regulations are strictly the responsibility of the user of these products.

Deposit Pitting:
Base metal pitting does not occur simply because a fume suppressant is being used. Fume suppressants can increase a pitting tendency caused by substrate imperfections, particularly with thicker deposits and bath impurities. Pitting is always related to improper cleaning or imperfections in the base material. Abusive preplate grinding or polishing can leave non visual surface debris that must be removed to avoid pitting whenever a fume suppressant is used. If pitting is a problem and the surface was prepared correctly, then it is likely due to minute base metal pinholes, microscopic substrate cracks, surface oxides or non-metallic inclusions in the base metal. Pitting can also be caused by stop-off residue, degradation of plastic material, as well as debris from wire brushes and grit blasting, or oils-organic materials in the bath. In some cases, this can be overcome by using an increased catalyst level and/or changing the reverse etch time. The use of Dura Prep scrubbing, glass beading or vapor blasting can remove surface debris while also providing better adhesion.