The beauty of biocatalysis: sustainable synthesis of ingredients in cosmetics

Covering: 2015 up to July 2021The market for cosmetics is consumer driven and the desire for green, sustainable and natural ingredients is increasing. The use of isolated enzymes and whole-cell organisms to synthesise these products is congruent with these values, especially when combined with the use of renewable, recyclable or waste feedstocks. The literature of biocatalysis for the synthesis of ingredients in cosmetics in the past five years is herein reviewed.

Asthma-inducing potential of 28 substances in spray cleaning products-Assessed by quantitative structure activity relationship (QSAR) testing and literature review

Exposure to spray cleaning products constitutes a potential risk for asthma induction. We set out to review whether substances in such products are potential inducers of asthma. We identified 101 spray cleaning products for professional use. Twenty‐eight of their chemical substances were selected. We based the selection on (a) positive prediction for respiratory sensitisation in humans based on quantitative structure activity relationship (QSAR) in the Danish (Q)SAR Database, (b) positive QSAR prediction for severe skin irritation in rabbits and (c) knowledge on the substances' physico‐chemical characteristics and toxicity. Combining the findings in the literature and QSAR predictions, we could group substances into four classes: (1) some indication in humans for asthma induction: chloramine, benzalkonium chloride; (2) some indication in animals for asthma induction: ethylenediaminetetraacetic acid (EDTA), citric acid; (3) equivocal data: hypochlorite; (4) few or lacking data: nitriloacetic acid, monoethanolamine, 2‐(2‐aminoethoxy)ethanol, 2‐diethylaminoethanol, alkyldimethylamin oxide, 1‐aminopropan‐2‐ol, methylisothiazolinone, benzisothiazolinone and chlormethylisothiazolinone; three specific sulphonates and sulfamic acid, salicylic acid and its analogue sodium benzoate, propane‐1,2‐diol, glycerol, propylidynetrimethanol, lactic acid, disodium malate, morpholine, bronopol and benzyl alcohol. In conclusion, we identified an asthma induction potential for some of the substances. In addition, we identified major knowledge gaps for most substances. Thus, more data are needed to feed into a strategy of safe‐by‐design, where substances with potential for induction of asthma are avoided in future (spray) cleaning products. Moreover, we suggest that QSAR predictions can serve to prioritise substances that need further testing in various areas of toxicology.

We reviewed whether substances in spray cleaning products constitute a potential risk for asthma induction. For this, we identified 101 spray cleaning products for professional use and prioritised their ingredient substances by use of quantitative structure activity relationship (QSAR). We provide a review of 28 selected substances: we give conclusions on their asthma induction potential, as well as a discussion on the use of QSAR for prioritisation of substances, and the major knowledge gaps we encountered.

Copper-mediated reductive dechlorination by green rust intercalated with dodecanoate

A layered Fe^II-Fe^III hydroxide (green rust, GR) was intercalated with dodecanoate (known as GR_C12) and then amended with Cu^II (GR_C12(Cu)) before reaction with chloroform (CF), carbon tetrachloride (CT), trichloroethylene (TCE) or tetrachloroethylene (PCE). Reduction of CT by GR_C12(Cu) was 37 times faster than with GR_C12 alone before the active Cu species was consumed. The Cu mediated reaction followed the dichloroelimination pathway as observed for GR_C12 alone, with carbon monoxide (82.5%) and formate (26.6%) as main degradation products. Also, CF was reduced by GR_C12(Cu), which is not seen with GR_C12. Neither GR_C12(Cu) nor GR_C12 reacted with PCE or TCE. The chlorinated solvents can partition into dodecanoate interlayer but only small CS molecules (CF, CT) can transport through the dodecanoate interlayer. Copper(II) added to GR_C12 was reduced to Cu^I by Fe^II in GR, but Cu^I was not regenerated during the dechlorination. High resolution TEM showed that Cu was evenly distributed in the GR without formation of Cu nanoparticles on edges of GR. The active Cu^I sites are most likely located between the iron hydroxide layer and the hydrated negatively charged carboxylate groups in the interlayer of GR. This work shines new light on the Cu accelerated dechlorination by GR.