The evils of APEOs (alkylphenol ethoxylates) lurk everywhere. They’re in packaging, food products, furniture, spot cleaners and paint. They’re in the dust in our homes, and even our blood and urine. Concentrations of APEOs have been measured worldwide in surface waters, sediments and sewage.
Slow to biodegrade, APEOs are toxic to aquatic organisms and an endocrine-disruptor to higher animals, and therefore pose a significant risk to humans.
It’s no secret that APEOs are bad, and this leads us to the obvious question: If they’re so bad, why are they still in use?
The reality is that these nonylphenol compounds (NPEOs) are non-ionic surfactants with an emulsifying and dispersing action, which makes them suitable for a large variety of applications. And replacing them with materials that work as effectively is not easy!
In an effort to better understand the impact of APEO-free materials in the architectural coatings industry, we caught up with John Mangano, Technical Service Specialist at BASF.
What is the biggest challenge in replacing APEOs?
John Mangano: The main goal is to replace the APEOs without impacting the performance of the coating in a negative way. Part of what surfactants do is to hold the two phases together. If you think of it like this, in essence you have oil and you have water. Naturally the two would separate, so the surfactant works to bind the two elements together in a uniform mixture.
You can’t have a can of latex paint without a surfactant, so it’s necessary to replace the APEO with something that can do the same job.
Do the APEO-free additives provide a comparable performance?
JM: I would say they are comparable to what exists. The APEOs are easier to use. So, when you go to APEO-free it does take some formulation work to start matching the properties. The dosing is not always an equal replacement in a formulation. You need to adjust the dose level, usually upwards as a percentage of the formulation.
We're talking about a material that's used at 0.25 to 1 percent of the total formulation. So, we could be talking about using 0.25 percent versus 0.3 percent to get the dosing right.
Are there any regulations surrounding the use of APEOs in North America?
JM: As far as coatings are concerned, Europe has regulations, but I am not aware of any federal state regulations banning the products here. What’s happening in our industry is more of a voluntary type of compliance.
Now, if the coatings manufacturers are shipping product to Europe, then they have to be aware of those regulations.
If there are no regulations in North America, where are the demands for APEO-free coatings coming from?
JM: There was a big interest a few years ago when the first conversions occurred, but there has been a renewed interest this year, or starting late last year.
Recently, demand is being driven by the green or sustainable attitudes of big box stores, like Home Depot and Wal-Mart. They want to build a reputation of being environmentally responsible, so part of that is selling APEO-free paint products.
JM: We are working on next-generation type technology now to give consumers better washability and better tannin-block resistance. Basically, what this means is that if something gets on the wall — food, mud, wine, crayons or even lipstick — it will be much easier to wash off without damaging the paint finish.