Why are solvent-based wallpaper inks toxic?

Inks are made of either mostly water, or mostly solvent. Solvents are chemicals that dissolve other chemicals into solutions, and typically are very smelly, releasing harmful VOCs into the air. They come from petroleum, and some are made with known carcinogens like toluene, benzene, and formaldehyde. Because of this, solvents are one of the priority classes of chemicals to avoid. Whether water- or solvent - based, many other chemicals are mixed in to make sure the ink prints evenly, is shiny, and is fade-resistant.

What are solvents?

Solvents are chemicals that keep things in liquid form until they are used. They are used in paints and stains and other liquid-based home products, too, since they help keep substances liquidy and evenly dispersed until application. They evaporate from products as they dry, and inhalation is one of the ways we are exposed. They can also be absorbed through the skin if you come into contact with them.

What is ECO-solvent ink?

ECO-solvent ink is still solvent-based, but it’s a milder solvent without as many VOCs as standard ones. They can be made with up to 50% plant-based materials like soy, or even the less-toxic portion of petroleum. Therefore, they are a better choice than standard inks, but not as healthy as those that are water-based.

What is titanium dioxide?

Titanium dioxide is a naturally-occurring mineral. It is sometimes used in inks, and in this format, is considered safe to touch.

It’s used in sunscreens in both the EU and US and in the US, is often found in brightly colored processed foods, and pharmaceutical medications. The EU doesn’t allow it in food, as it is associated with DNA damage. It can also be dangerous for workers that inhale it.

Are clay-based coatings safe?

Generally, yes, but it might depend on whether other ingredients are mixed in with clay. Clay-based means clay is only part of the coating. The rest of the coating can be made with resins, polymers, and other undisclosed additives, so it’s good to check.

What harmful finishes are added to wallpaper?

Wallpaper can be surprisingly chemically intense.

➜ Heavy Metals: A 2010 investigative report found that over 50% of PVC wallpapers contained lead, cadmium, chromium, tin, and mercury.

➜ Flame Retardants: Flame Retardants are well-known endocrine disrupting chemicals and do not meaningfully reduce flammability, but are still routinely added to wallpaper. Companies are not required to disclose whether their product contains Flame Retardants.

➜ PFAS: PFAS chemicals are added to wallpapers to make them more water-resistant or stain-resistant. PFAS are linked with lowered immune function, metabolic issues, reduced fertility, and a host of other health problems. They are also “forever chemicals,” meaning they do not break down in the environment. Companies are not required to disclose whether their product contains PFAS.

➜ Plasticizers: Plasticizers are chemicals added to wallpapers to make them more flexible and easy to hang. Phthalates and BPA are two well-known examples. They interfere with your hormones and are linked with a variety of reproductive and developmental issues.

➜ Antimicrobials: Also called biocides or mildewcides, antimicrobials are added to wallpaper that doesn’t allow for moisture to pass through (like PVC). They disrupt hormone function, are associated with developmental and reproductive effects, allergen sensitivity, and antibiotic resistance. For these reasons, they are considered one of the classes of priority chemicals to avoid. Inherently antimicrobial wallpaper is a healthier option— ones that have microventing for air and water permeability, or are made with natural, breathable cellulose.

Why is PVC wallpaper bad?

PVC is the most common wallpaper material, especially for commercial use, because it’s so durable. However, PVC is a priority chemical to avoid, as agreed upon by international groups because of its toxicity during its entire lifecycle— the production, use, and degradation stages. The US Green Building Council declares that PVC is “consistently among the worst materials for human health impacts.”

Vinyl chloride, the molecule used to make PVC, is an established carcinogen that causes lung, brain, liver, and rare cancers such as hepatic angiosarcoma. This is why the vinyl chloride spill in Ohio in 2023 was such cause for concern.

A 2010 investigative report found that over 50% of PVC wallpapers contained lead, cadmium, chromium, tin, and mercury. Phthalates are also added, as well as other chemicals to alter its rigidity, transparency, or softness. These are not chemically bound within the PVC structure, and easily leach out for absorption into the body.

At the end of its life, when people throw away PVC products into their trash, it is burned in municipal waste incinerators, releasing dioxins into the air. Dioxins are one of the most hazardous chemicals for people and the planet.

Last, vinyl wallpaper doesn’t “breathe” or allow air and moisture to pass through, necessitating use of a biocide, fungicide, or mildewcide coating. These antimicrobials disrupt hormone function, are associated with developmental and reproductive effects, allergen sensitivity, and antibiotic resistance.

What are biocides and why are they in wallpaper adhesives?

Biocides, also called mildewcides, fungicides, or antimicrobials, are added to wallpaper that doesn’t allow for moisture to pass through (like PVC). They can help prevent the growth of mold and mildew, but they disrupt hormone function, are associated with developmental and reproductive effects, allergen sensitivity, and antibiotic resistance. For these reasons, they are considered one of the classes of priority chemicals to avoid.

Is EVA adhesive safe?

EVA is short for ethylene vinyl acetate. Even though it has the word vinyl in it, it’s chemical structure and properties are very different than PVC (polyvinyl chloride, also just called “vinyl”). It is the sticky part of peel-and-stick wallpaper. It is not carcinogenic, and is generally a much safer plastic-based adhesive choice.