Why your lab gloves might be faking microplastics

In 2020, researchers found that gloves used in labs introduced a chemical called stearate into samples, which interfered with the detection of microplastics in scientific studies.

When scientists handle environmental samples while wearing common nitrile or latex gloves, chemical residues from the gloves can mimic the spectral signature of microplastics, causing analytical tools to incorrectly identify them as microplastics at a rate of about 2,100 per square millimeter, leading to overestimated counts in environmental studies.

Microplastics from gloves made with stearates tend to break into very small pieces under 10 micrometers, which are harder to detect and more likely to spread through contact with surfaces, making them a focus for environmental and health monitoring.

Cleanroom nitrile gloves leave behind much less stearate contamination than regular nitrile or latex gloves, which reduces interference in microplastic measurements during laboratory analysis.

Current methods for identifying microplastics using spectral libraries often fail to tell apart stearate salts from polyethylene particles when the particles are smaller than 2 micrometers, because the signals are too weak to detect key chemical differences, even when those differences exist.