Microplastics are not just an ocean problem anymore. Researchers have reported plastic particles in human stool, lung tissue, placenta, blood, breast milk, semen, and other samples. The science is still young, but the direction is plain enough: small plastic particles are getting into the human environment, and some are getting into the human body.
Dishwasher detergent is a small part of that larger plastic story, but it is worth talking about clearly. Many modern dishwasher pods use a dissolving plastic film, commonly polyvinyl alcohol, also called PVA or PVOH. That film is designed to dissolve in the wash, but dissolved does not always mean gone from the world.
Old Chemistry chose powder, not pods, for a simple reason: a measured powder can clean without sending a plastic wrapper through every cycle. That does not make one dishwasher load the whole microplastics problem. It does mean the design choice is real, practical, and easy to understand.
Our dishwasher detergent powder is built around that old-fashioned standard: no pod film, no added fragrance, and ingredients with named jobs.
What are microplastics?
Microplastics are usually defined as plastic particles smaller than 5 millimeters. Nanoplastics are even smaller. They can be manufactured small, as with some old microbead uses, or they can form when larger plastic items break down.
The health question is not only whether plastic exists nearby. It is whether small plastic particles can be inhaled, swallowed, moved into tissues, carry other chemicals, or trigger biological stress.
A 2023 review on human biomonitoring summarized the state of the field this way: microplastics have been detected in human blood, urine, stool, lung tissue, breast milk, semen, and placenta. The same review said potential health risks suggested by experimental evidence include inflammation, oxidative stress, and DNA damage, but also emphasized that the field is still early.
Source: Human biomonitoring of microplastics and health implications: A review
What does this have to do with dishwasher pods?
Most dishwasher and laundry pods use a water-soluble film made from polyvinyl alcohol. PVA is a synthetic polymer. In ordinary language, it is a kind of plastic made to dissolve in water.
A 2021 paper on PVA from laundry and dish detergent pods estimated that, in the United States, about 17,200 metric tons per year of PVA were used from laundry and dish detergent pods. The model estimated about 10,500 metric tons per year reaching wastewater treatment plants. Based on the literature they reviewed, the authors estimated that a substantial share could leave treatment through sludge or water rather than fully degrading.
That study is about environmental fate, not direct human disease from dishwasher pods. Still, it raises the practical question Old Chemistry cares about: if a cleaning product does not need a dissolving plastic film, why add one?
Important caution: PVA is debated
This is where the honest wording matters.
PVA pod film is water-soluble. It does not behave exactly like a visible shard of polyethylene or polypropylene. Some manufacturers and industry groups argue that properly formulated PVA biodegrades under the right conditions. Some environmental researchers argue that those conditions are not guaranteed in real wastewater systems, and that the fate of PVA is not understood well enough.
So the strongest truthful claim is not “dishwasher pods poison people.” That would be sloppy and unserious.
The stronger claim is this: dishwasher pods commonly use a water-soluble plastic film, the environmental fate of that polymer is contested, and a powder detergent can avoid that film entirely.
That is enough reason for a plain powder.
What scientists have found in the human body
The human evidence is growing, but it is not complete. Here are some of the stronger signposts.
Human blood
A 2022 study reported plastic particles in human whole blood from healthy volunteers. It identified several common polymers, including polyethylene terephthalate, polyethylene, and styrene polymers. The study was small, but important because it showed that plastic particles can be measured in blood.
Source: Discovery and quantification of plastic particle pollution in human blood
Human placenta
A 2021 study found microplastic fragments in human placentas. The authors reported 12 microplastic fragments in 4 of 6 placentas studied. This does not prove a health outcome by itself, but it is a serious exposure finding.
Source: Plasticenta: First evidence of microplastics in human placenta
Human lung tissue
Human lung studies have also reported microplastics in tissue. PubMed lists studies including “Presence of airborne microplastics in human lung tissue” and “Detection of microplastics in human lung tissue using µFTIR spectroscopy.” This matters because inhalation is one of the main exposure routes researchers worry about.
Source: PubMed search: microplastics human lung tissue
Human stool
Microplastics have been detected in human stool, which is consistent with ingestion exposure from food, water, dust, packaging, and other sources.
Source: Detection of Various Microplastics in Human Stool
What are the possible effects on the human body?
A 2024 rapid systematic review looked at digestive, reproductive, and respiratory outcomes. It included a small number of human observational studies and more animal studies. The authors concluded that microplastic exposure is suspected to adversely affect reproductive, digestive, and respiratory health, while also noting limits in the evidence.
The main biological concerns include:
- Inflammation, especially in lung and digestive tissues.
- Oxidative stress, which means cellular stress from reactive molecules.
- Physical irritation from particles, depending on size, shape, and dose.
- Chemical transport, because plastic particles can contain additives or adsorb contaminants.
- Possible effects on reproductive markers, based mainly on animal and limited human evidence.
A 2024 New England Journal of Medicine observational study also found microplastics and nanoplastics in carotid artery plaque samples and reported an association with cardiovascular events. That study does not prove that plastics caused the events, but it is one of the reasons the subject has become harder to dismiss.
Source: Microplastics and Nanoplastics in Atheromas and Cardiovascular Events
What we can say without pretending to know more than science knows
The science does not support panic. It also does not support pretending this is nothing.
A careful reading says:
- Microplastics are widespread in the environment.
- Human exposure is documented.
- Plastic particles have been measured in multiple human tissues and fluids.
- Animal and cell studies suggest plausible harm pathways, including inflammation and oxidative stress.
- Human outcome evidence is still developing.
- Reducing unnecessary plastic exposure is a reasonable precaution.
That last point is where household products matter. Not because one pod is the whole problem, but because repeated small design choices add up.
Why Old Chemistry uses powder instead of pods
Powder is old technology, but sometimes old technology is the better technology.
A dishwasher powder does not need a dissolving plastic wrapper. It lets the user measure the dose. It lets the product page explain what is in the formula. It keeps the product closer to the thing doing the work: the ingredients.
You can read the plain-language ingredient pages here:
- Sodium carbonate, the alkaline worker.
- Sodium bicarbonate, the steadying mineral.
- Citric acid, the mineral manager.
- Detergent-grade protease, the food-soil enzyme candidate under documentation and safety review.
And you can see the product here: Old Chemistry Dishwasher Detergent Powder.
The Old Chemistry standard
Old Chemistry is not built on fear. It is built on inspection.
If a product can avoid added fragrance, avoid dye, avoid a pod film, and explain its ingredients plainly, it should. That is the kind of peace of mind we mean: not a miracle claim, not medical advice, and not a scare campaign. Just fewer unnecessary mysteries between the cleaning product and the home.
Dishwasher powder with old mineral chemistry and plain modern labeling.