A lot has been written and claimed lately by companies offering “safer” solvent inks. They claim many safer attributes like no VOCs, biodegradable, “HAPs free”, nickel free, etc. What do these terms mean and how do you judge the true safety to workers and the environment of these inks? Here are some facts surrounding these terms to help you decide which inks are best for you and how you should safely handle them.

DEFINING HAPs

HAPs is an acronym that stands for Hazardous Air Pollutants. The Environmental Protection Agency provides a list of chemicals and classes of chemicals that fall under HAPs. If a solvent ink contains one or more of these listed chemicals, it contains HAPs. The hazard might be the chemical itself and what it does to your employees and the environment; or it may cover a class of materials that are classified as hazardous. If you want to check to determine whether there is a HAPs material in a particular ink, you can request a Materials Safety Data Sheet (MSDS) from the ink provider, and then compare the chemicals listed on the MSDS with the list provided on the EPA website (www.epa.gov/ttn/atw/orig189.html).

InkTec and many other ink manufacturers know that removing HAPs is important for both the environment and the graphics industry.

Each chemical has a CAS number associated with it, which means the substance has been registered with the Chemical Abstracts Service. The CAS number is important since chemists often have several ways of naming chemicals and the CAS number is unique to the chemical, no matter how it is named.

For chemicals, like pigments or dyes, there may only be a component in the chemical which makes it HAPs listed. For example, nickel is commonly used in the yellow pigments in inkjet inks where outdoor lightfastness is important. Nickel is a listed component on the HAPs list and the chemical containing it must also be listed as a carcinogen.

Chemicals that help to clean or degrease the surface of the substrate on which you are printing are frequently HAPs-listed materials. They are needed for good wetting and adhesion of the ink to the substrate. It is difficult to find agood degreaser that is not HAPs listed. It is hard to develop an ink which is HAPs-free and yet provides good adhesion properties particularly to vinyl.

A growing number of ink makers are offering inks with a HAPs-free claim. For example, INX Digital, San Leandro, Calif., offers its range of ECO formula inkjet inks, and A.T. Inks, Charlotte N.C., sells a line of Bio Inks which are sold as being HAPs-free and biodegradable.

LOW-ODOR INKS

The big push now is to provide low-odor solvent inks. This is a two-edged sword: if the solvent inks do not smell bad they may be more pleasant for the operator to work with, but then as a result the operator—taking fewer precautions against solvents—may actually become exposed to higher levels of odor-free solvent fumes. It is important to remember that solvent printers produce a lot of solvent fumes, and these should be ventilated as a matter of principle—whether they smell bad or not. I have heard some printer manufacturer’s representatives suggest that no ventilation is required, but ventilation should always be used for solvent printers.

Among its line of products, INX Digital, San Leandro, Calif., offers a range of ECO formula inkjet inks with the goal of reducing Hazardous Air Pollutants.

VOCs AND BIODEGRADABILITY

Volatile Organic Compounds (VOCs) is another government classification; this one is for compounds which, when emitted into the atmosphere, can react to form ozone, a component of smog. However, not all volatile organic compounds are VOCs since some do not react in the environment to create ozone. Yes, it’s a little confusing.

A good example is the major solvent used in biodegradable, or partially biodegradable, inks called ethyl lactate. It is a chemical derived from corn or other crops, and when released into the atmosphere biodegrades to harmless materials without creating ozone. It is volatile organic compound in that it easily evaporates into the atmosphere, but is not a government-listed VOC because once released, it does not create ozone.

Phoenix-based Mutoh America offers green inks, Mubio and Mutoh MP, which contain this chemical. Mutoh claims biodegradability in its literature and indeed this component does biodegrade. Keep in mind, however, that the pigments do not biodegrade even if the binders and solvents do. So no inkjet ink is in fact 100 percent biodegradable.

NICKEL COMPOUNDS

Nickel is an ingredient commonly found in many yellow ink pigments and dyes. Metallized dyes and pigments are frequently used when outdoor lightfastness is needed. Many ink manufacturers offer different yellow inks—both those with and those without nickel containing pigments. Epson America, Long Beach, Calif., sells a nickel-free ink called UltraChrome GS.

The MSDS for the ink must clearly identify the presence of nickel and indicate that it is a carcinogen. In normal inkjet applications this does not pose much of a hazard if normal precautions are taken, especially ventilation. Remember the inkjet printing process inherently generates some ink spray which may leave the printer and be inhaled by those nearby. Although the amounts may be small they may pose an unnecessary health risk.

CONCLUSION

Ink manufacturers of solvent-based inks are focusing more and more on inks which smell less, are HAPs free, are at least partially biodegradable and are nickel free. The choice is yours and you should make an informed decision in order to protect your employees and the environment while providing your customers with great durable graphics.