A Volatile Organic Compound (VOC) is a term used by the EPA and other regulatory agencies in reference to any carbon-based compound that can evaporate from solution into the atmosphere and react with oxygen in the presence of light to form ozone, thus contributing to smog problems.  The EPA Method 24 is used to test compounds for VOC content, and it categorizes as VOCs all compounds with sufficient vapor pressure to evaporate from liquid to gas after being heated to 230 oF for at least 1 hour.  Obviously, this method covers thousands of chemical compounds.  In fact, almost all carbon-based compounds that exist as a liquid at room temperatures and atmospheric pressure qualify as VOCs under this testing method.  There are a few such compounds that are not classified as VOCs because they have been tested and found to have negligible photoreactivity when released into the atmosphere.  The vast majority of these, however, are halogenated solvent compounds, and therefore are poor choices for use in as press washes due to the hazards they pose to human health.

Due to the oily nature of the printing inks that must be cleaned from press equipment, aqueous solutions are only marginally useful for dissolving and removing these inks from the press.  Most press washes employ organic solvents that can quickly dissolve these inks and wipe the ink-in-solvent mixture from the press.  

There exist solvent compounds that do not evaporate into the atmosphere and contribute to the formation of ozone, but because they do not evaporate (or only evaporate slowly), they tend to leave a thin, oily residue on the surface to be cleaned.  The presence of this surface can cause ink to be excessively dispersed, and therefore leads to blurry images.  This is unacceptable to most printers.

The problem that printers face when choosing a press wash is that they can either choose a high-VOC compound that will contribute to smog, or they can choose a slow-evaporating low-VOC compound that will leave an oily residue on blankets and rollers, which must be wiped away manually or “run out” by printing several copies of low-quality prints just to run the paper through the press to remove the oil residue.

To get around this quandary, several prominent chemical companies are producing “low-VOC” washes that are merely standard press washes that have been emulsified and diluted in water.  Since “Low-VOC” washes are loosely defined as washes that contain less than 3.5 lbs/gallon of VOCs, a chemical company could just take its standard 7 lb/gallon VOC solvent and emulsify 0.4 gallons of it in 0.6 gallons of water, resulting in a press wash that contains 2.8 lbs/gallon of VOCs.  Most companies who produce such washes sell them at premium prices, hoping that printers seeking VOC emission compliance will blindly pay the extra money for a product that is not significantly improved or altered for eco-friendliness, but merely watered down.

We at Tersus Chemical, on the other hand, are truly committed to environmental responsibility, and our product formulations prove this.  Aware of the practical limitations of ink-dissolving compositions that cannot evaporate, we produce press washes that necessarily contain a certain amount of VOCs, but are completely devoid of petrochemicals and other nonrenewable resources.  All of our products are completely biodegradable and safe for use.  We also produce some extremely low-VOC press washes that are not merely watered down to reduce VOC content, but are made with non-VOC solvents.  In order to save our customers time and money, we produce a two-step wash system that allows them to eliminate the oily residue problems created by the necessarily slow evaporation of non-VOC solvents by merely wiping away the residue with water.