Water-based paints: Less stinky, but some still contain potentially hazardous chemicals

AMERICAN CHEMICAL SOCIETY

Choosing paint for your home brings a lot of options: What kind of paint, what type of finish and what color? Water-based paints have emerged as “greener” and less smelly than solvent-based options. And they are often advertised as containing little-to-no volatile organic compounds (VOCs). But, according to research published in ACS’ Environmental Science & Technology Letters, some of these paints do contain compounds that are considered VOCs, along with other chemicals of emerging concern.

Paint consists of four ingredients: pigments, binders, additives and a liquid. If the liquid is water — as in latex and some acrylic paints — it’s classified as a water-based paint, rather than solvent-based. Historically, solvent-based paints were easy to apply and durable, though they released foul-smelling VOCs into the air both during and after application, stinking up a newly painted room. These airborne VOCs can cause respiratory irritation and headaches, among other potential health problems, especially in high concentrations or over long periods of time. Despite water-based paints sporting labels with “zero-” or “low-VOC,” their formulations could contain potentially dangerous chemicals of their own. So, Ying Xu and colleagues wanted to understand more about these paints’ formulations. The team notes that there are differing definitions of what constitutes a VOC, some of which are stricter than others, including the World Health Organization’s definition used in this research.

The team collected 40 water-based paints from around the world, all ranked among the top 70 most-sold brands, and many labelled as zero- or low-VOC. Both dry and wet samples were analyzed by gas chromatography-mass spectrometry to determine their composition.

• Twenty semi-volatile organic compounds were identified in concentrations ranging from 10 to 35,000 parts per million. While less likely to be in a gaseous form, these can still persist indoors for years, often incorporated into dust.
• Endocrine-disrupting phthalates, which act as binders, were largely absent in the tested paints. However, several phthalate-replacement chemicals were detected — their toxicities are still being assessed.
• Nearly half the analyzed samples contained measurable amounts of isothiazolinones — preservatives that have been linked to skin irritation and asthmatic symptoms.
• In 24 of the wet paint samples advertised as either zero- or low-VOC, 11 different VOCs were detected at concentrations up to 20,000 parts per million.

These concentrations represent the chemical composition within the paint, not the air. Further studies are required to understand how much of these potentially hazardous compounds become airborne as painted surfaces are drying. The researchers say that this work could allow for the design of safer paint products in the future.

The authors acknowledge funding from the National Natural Science Foundation of China.

The paper’s abstract will be available on April 3 at 8 a.m. Eastern time here: http://pubs.acs.org/doi/abs/10.1021/acs.estlett.4c00052  

###

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

Note: ACS does not conduct research, but publishes and publicizes peer-reviewed scientific studies.

Follow us: X, formerly Twitter | Facebook | LinkedIn | Instagram

---

JOURNAL

Environmental Science & Technology Letters

DOI

10.1021/acs.estlett.4c00052 

ARTICLE TITLE

Chemicals of Emerging Concern in Water-Based Paint Products

ARTICLE PUBLICATION DATE

3-Apr-2024