On October 1, 2026, the American Chemical Society issued a press release about a study published in Environmental Science & Technology: researchers led by Jinlong Wang describe an insert that fits under a trash can lid, powered only by sunlight, to curb bad odors. The release also mentions activated charcoal and its limits. Since that is our field, here is what to take from it, without overstating it in either direction.

What the study describes

The device contains a manganese-oxide-based catalyst, activated by sunlight concentrated through a transparent membrane. It targets acetic acid, a vinegar-smelling compound that forms as food decays, and breaks it down. According to the release, it worked for more than 40 days in natural sunlight in tests with decaying fruit, bread and wine, including in humid conditions.

What the release says about activated charcoal

The release notes that activated charcoal filters placed under the lid can help contain the smell, but that they work less well in hot, humid environments. This is background context: we only read the press release, not the full study, and we do not know whether that remark rests on measurements made in the study itself.

Why humidity matters for activated charcoal

Activated charcoal works by adsorption: the molecules to capture attach to the surface of its many pores. In hot, humid air, water vapor can compete with odor molecules for those same sites, which can reduce its capture capacity. Its capacity is also limited: once the sites are occupied, it captures less, which is why upkeep matters. Finally, some light molecules, such as ammonia or formaldehyde, are harder for untreated activated charcoal to capture.

Capture or destroy: two different approaches

Activated charcoal captures molecules without transforming them: it traps, it does not destroy. The study’s catalyst, on the other hand, breaks down the targeted compound. These are two distinct logics: one is a device described in a scientific publication for a specific case, the other a versatile material with limited capacity. It would be rash to call one better than the other: it all depends on the use.

What this changes for your coalnest sachets

• Deal with the source first. Taking the trash out regularly, cleaning the bin, closing the bag properly and airing the room remain the basics. A sachet is a complement, not a solution on its own.
• Favor everyday enclosed spaces. Wardrobe, drawers, shoes, car: these are the uses our sachets are designed for. They are not meant to handle an intense odor source on their own, such as a trash can in the middle of summer.
• Remember to recharge. As in our care guide, we recommend about 2 to 3 hours in full sun, roughly every 4 weeks.

At coalnest, we would rather tell you where a sachet is useful and where it is not enough: that is also how you pick the right tools for your home.

Discover the coalnest purifying kits

Source: American Chemical Society press release relayed by EurekAlert (October 1, 2026), about a study published in Environmental Science & Technology (DOI: 10.1021/acs.est.6c07573). Information about the study comes from the press release, not from reading the full paper.