Posted on Tuesday 09th December, 2014
ACL Update on HCFC-225 (AK 225) Phase Out
ACL Update on HCFC-225 (AK 225) Phase Out and Ban
The EPA ban and elimination of AK 225 is a current topic of continuing concern in the area of electronics cleaning and printed circuit board rework and repair. The banning of AK 225 effective January 1, 2015 will limit the number of available types of solvents for electronics cleaning and will once again change the solvent cleaning landscape in our industry. It’s important to understand what replacement chemistries will be available in 2015 and how this will affect end-users.
HCFC-225 falls under EPA’s Clean Air Act as a Class II ozone depleting entity and is now defined as an Agency controlled substance. It is thus deemed unlawful for any person to engage in interstate commerce of the solvent or any use of the substance unless it has been used, recovered, or recycled or used to produce another chemical, or finally, used as a refrigerant (until 1/1/2020). End-users may use and continue to purchase aerosols containing HCFC-225 made before January 1, 2015. Beginning January 1, 2015, HCFC-225 can only be used in the manufacture of end-user cleaning products if it has been used, recovered, and recycled, as per the Clean Air Act.
HCFC-225 is a cleaning solvent mixture of two isomers, HCFC-225ca and HCFC-225cb (commonly known as AK 225). AK-225 has many unique properties, including its ability to form azeotropes, strong solvency, and thermal stability, which makes it good for use in vapor degreasing. AK-225 is nonflammable, has a low acute toxicity, low viscosity, high density, and low surface tension. This list of great performance characteristics is what makes AK 225 such a great general purpose precision cleaning solvent. It is also why this particular solvent has been so difficult to replace with alternatives.
The Agency has approved more than 300 substitutes for multiple applications. Potential substitutes for HCFC-225 include DuPont Vertrel Solvents (Vertrel XF), n-Propyl Bromide(nPB), Trichloroethylene (TCE; mostly Chinese sources today), 3M hydrofluoroethers (HFEs), and Honeywell’s Solstice Performance Fluid (Solstice PF).
DuPont’s Vertrel has characteristics similar to AK 225, but is much more environmentally friendly. Solvents containing nPB work well for difficult precision cleaning applications, but they are not considered environmentally friendly. From a health and environmental perspective, both nPB and TCE are not good replacements for AK 225 due to their low exposure limits and suspect carcinogenicity. EPA is also currently evaluating the flammability limits of nPB. Additionally, TCE is an overly aggressive solvent making it unsuitable for use with most plastics and elastomers.
From an environmental standpoint 3M HFEs are great as they have been granted VOC exemption. Honeywell’s HFO-1233zd(E) has a low global warming potential and is non-flammable. However, cost to the end-user for familiar cleaning applications may be an issue.
Because HCFC-225 is commonly used in high end, class 3 applications (like aerospace, medical, and biotech), qualification of replacement solvents is a difficult and complex process. It is not too early to start the process, and there are many choices to meet most every requirement. ACL has encouraged its end-use customers to initiate the replacement qualification process early to ensure solvent compatibility, performance, and product availability.
Considering all the facts and chemical replacement requirements from the EPA, ACL Staticide has developed a line of solvent chemistries and formulations designed specifically as AK 225 replacements. Our new line includes both flammable products and nonflammable products with our nonflammable alternatives developed specifically for AK 225. In particular, our new ACL 8624 A4 All Purpose Flux Remover & Cleaner has been formulated as a universal performance replacement for all former AK 225 applications. It has many of the same great features of AK 225, but without the ozone depletion potential. It is recommended that the product be tested on plastics prior to use to determine plastic compatibility with each customer’s unique application and process. Contact ACL Staticide at 1-800-782-8420 for more information regarding our AK 225 replacements.