VOC-Exempt Solvents for Planet-Healthy Paint
Summertime is the season for DIY paint projects. Whether it’s a fresh coat on your backyard fence or a project to spruce up an old dresser, many consumers choose to time their projects for this time of year. This is especially true for 2020, since COVID-19 quarantine measures have holed people up in their houses with little else to do besides getting creative with socially distant projects. If you’re a DIYer from California, you’re probably already familiar with the concept of “low VOC” paint. Even coatings industry professionals in other parts of the country deal with this term daily. Demand for safer and greener products is at an all-time high, and paint is no exception.
What is a VOC? According to the EPA, a VOC (volatile organic compound) is “any volatile compound of carbon, excluding methane, carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, ammonium carbonate, and exempt compounds which participates in atmospheric photochemical reactions”. Volatility is defined on a gas chromatograph as a function of elution time compared to a reference solvent – but exempt compounds can sometimes be categorized as volatile. Atmospheric photochemical reactions are reactions with oxygen at the tropospheric level (the level we live in) that create ozone. Exempt compounds are exempt because they do not participate in atmospheric chemical reactions.
Although ozone in the stratosphere (basically space) is essential for protecting Earth from UV radiation, tropospheric ozone is linked to many health and environmental hazards:
- Tropospheric ozone is a major greenhouse gas. It contributes to smog levels and has an impact on global climate change.
- As a large component of smog, it exacerbates respiratory diseases and permanently damages lung tissue. Long-term ozone exposure is linked to over a million premature deaths annually.
- Many crops are sensitive to excess ozone, with global agricultural losses estimated at $11-18 Billion annually (source)
Independent from the formation of ozone, many VOC compounds cause health hazards unrelated to their greenhouse gas potential. Solvents such as xylene and formaldehyde are associated with headaches, nausea, organ damage, and even cancer. It’s no mystery why industrial and household consumers are keen to move towards safer coating formulations!
Fortunately, the coatings industry is evolving to meet customer and environmental demands. The state of California has tasked the California Air Resources Board (CARB) and the South Coast Air Quality Management District (SCAQMD) with developing regulations and programs to protect the public from air pollution and fight climate change. They are national leaders in eco-friendly initiatives: the trail blazed in CA is often followed by the rest of the country.
In the coatings industry, the most important program is regulation of VOCs in coatings formulations. Regulations apply to all coatings used in the state of California, whether they are intended for industrial or consumer use. Given the health hazards associated with VOC solvents outlined above, many consumers are eager to jump on the low- to zero-VOC paint bandwagon. The current VOC regulations from SCAQMD are:
You might notice in the table above that VOC is expressed as a function of grams of VOC per liter of coating. From a legal standpoint, the “regulatory VOC” can be found using the formula:
VOCregulatory = grams of VOC / ( Lpaint – Lwater – Lexempts)
Notice that VOC exempt compounds are not included with this calculation, which means that paint companies are free to formulate coatings with exempt solvents in order to minimize the VOC profile. No greenhouses gases, no smog, and fewer carcinogens! This is where the list of exempt solvents published by the EPA is especially useful – formulators can use it as a guide to choose solvents for new projects, or to replace solvents in old ones. The full list can be found here.
Silver Fern Chemical has been supporting paint companies in North America as a supplier of low-VOC solvents for over a decade. We regularly stock over a dozen of the 68 listed exempt chemicals, including glycol ether DPNP, DPNB, and PPH, ethyl 3-ethoxypropionate, t-butyl acetate, methyl acetate, and PCBTF. We are proud to help our customers and DIY painters make the world a greener place, one eco-friendly paint can at a time.