4-Hydroxy-TEMPO

4-Hydroxy-TEMPO (CAS 2226-96-2), commercially known as TEMPOL, is a stable nitroxide radical used across polymer, pharmaceutical, and personal care manufacturing. It functions primarily as a polymerization inhibitor and radical scavenger. This chemical acts as a process stabilizer, preventing premature crosslinking or degradation during production and storage. In polymer and resin manufacturing, it inhibits unwanted radical polymerization in monomer streams.

By protecting product integrity during transport and storage, it ensures high-quality outcomes. Pharmaceutical manufacturers use it as a controlled radical mediator in active ingredient synthesis and as an antioxidant stabilizer. In personal care, it is incorporated into formulations requiring oxidative stability. This is particularly important where free radical chain reactions would compromise shelf life or efficacy in the final consumer product.

TEMPOL also serves as a catalyst in selective oxidation reactions, including the conversion of primary alcohols to aldehydes. This functionality is essential in fine chemical and API synthesis workflows for modern medicine. The product is supplied as a crystalline solid, typically as an orange to red-orange powder or granules. It is available in technical and high-purity grades, with purity specifications commonly ranging from 97% to 99%+.

These grades are suitable for research, pharmaceutical, and industrial applications. Packaging options range from small laboratory quantities to bulk industrial supply, depending on specific application requirements and scale.