Press release submitted on behalf of IGM Resins.
IGM Resins, Waalwijk, The Netherlands, announced the reclassification of 1-Hydroxycyclohexyl-phenyl ketone. 1-Hydroxycyclohexyl-phenyl ketone, (CAS no. 947-19-3), commercially known as Omnirad® 184 and Omnirad® 184D in iGM Resins portfolio, is a widely used photoinitiator in the energy curing industry, valued for its consistent performance across a wide range of applications. The product is registered in Europe by
IGM Resins under Annex IX.
The European Chemicals Agency (ECHA) required IGM Resins, as lead registrant, to conduct additional in vivo genotoxicity testing (OECD 414). The new toxicological results are showing that the product is a reprotoxic substance. As a result, Omnirad® 184 is now reclassified with immediate effect as Reproductive Toxicity Category 1B under EU REACH regulations. This regulatory shift introduces new compliance obligations for formulators and manufacturers, especially in Europe and North America. This change marks a significant change in the handling and usage of this product across the industry.
Our tested solutions
While a universal substitute may not suit every formulation, we recognize the importance of offering options that align with both performance needs and regulatory compliance. Thanks to our constant innovation and ongoing development of photoinitiators, iGM Resins is well positioned to offer a broad range of solutions, from standard products to advanced, high-performance alternatives.
The closest alternative is Omnirad® 1173. This is also a low molecular weight photoinitiator with good reactivity under Hg-lamp, low-yellowing and excellent formulation compatibility. Its liquid nature makes it easy to handle. Its higher evaporation rate could lead to easier dirty collection on the lamps and higher perceived odour when on the press. Produced at the Mortara, Italy site, it offers reduced delivery times for customers in Europe and a complete Life Cyle Analysis.
For more sensitive applications and if the highest reactivity and lowest yellowing level are required, Omnirad® 601 is an excellent choice. This solid photoinitiator is especially suited where very low odour is required. Its solubility is more limited than Omnirad® 184.Omnirad® 601 combines a higher molecular weight with a higher functionality, leading to significantly lower odour and emissions in general.
Intermediate option between Omnirad® 1173 and Omnirad® 601 is our economical solution Omnirad® 2509. This is a liquid photoinitiator, bringing good surface cure, low yellowing and good formulation stability for both inks and clear varnishes with an affordable cost in use too- a perfect combination of performance and economics.
Omnirad® 184 is an efficient, non-yellowing photoinitiator, used to initiate photopolymerization of (meth)acrylate monomers and oligomers under a wide variety of conditions. Chemically speaking, Omnirad® 184 belongs to the class of alpha hydroxy ketones (AHK), which are Type I photoinitiators. IGM Resins is offering a range of mono- and di-functional AHK products. The complete list can be found in our product brochure.
Tailored Support and Technical Expertise
Our technical experts are ready to support customers in identifying the most suitable alternatives to Omnirad® 184. We work case by case, ensuring each application—whether in coatings, inks, or adhesives—receives a tailored approach. This includes formulation guidance, performance testing and regulatory advice to ensure minimal disruption during the transition.
Conclusion
The reclassification of 1-Hydroxycyclohexyl-phenyl ketone reinforces the need for safer and more sustainable solutions. iGM Resins remains committed to guiding our partners through this change with reliable alternatives, expert support and a continued focus on regulatory alignment and product performance.
About IGM Resins
IGM Resins specializes in the development, manufacture and supply of products and technical services to the global energy curing coatings and inks market. IGM Resins develops, produces and distributes a full range of radiation curable materials including photoinitiators, energy curing oligomers and monomers, and additives from manufacturing facilities in Europe, Asia and the US, supported by technical labs in each of these regions to help create next generation energy curable coatings and inks.
For more information, visit www.igmresins.com.
