Link to Preservative Safety Index Data
This project provides recommendations for finding safer preservatives for laundry detergent, hand soap, and dish soap, aiming to replace phenoxyethanol. It looks for alternatives that are just as effective, or even better, but with fewer health and environmental risks. Methylisothiazolinone (MIT) is included for comparison. Working with industry partner ECOS, key factors for selecting preservatives were identified, such as pH compatibility, product performance (like foaming and stain removal), and stability.
The study used the GreenScreen method to assess potential alternatives, considering preservatives from various sources like food preservative lists, EPA-approved chemicals, and the cosmetics industry. Seven preservative strategies were identified: carboxylic acids, natural options, peptides, hydroxamic acids, esters, polyols, and phenyl alkyl alcohols. For each, the report outlines technical performance, health and environmental impacts, and remaining questions.
Two alternative strategies were also proposed: solid formulations (powder or tablets) since they need fewer preservatives, and machine learning to find better preservative combinations. The report highlights four promising options:
- Carboxylic acids (proven, affordable, but need low pH)
- Peptides (like ɛ-poly-L-lysine, low toxicity but expensive)
- Esters (like sorbitan caprylate, low hazards but low effectiveness)
- Phenyl alkyl alcohols (like benzyl alcohol, effective but higher hazards)
Further research is needed to explore formulation compatibility, consumer perception, and suitability for specific partners.