To reduce your screen printing shop’s environmental impact and avoid potential penalties, you have to understand how to properly dispose of your ink.
To make sure you’re disposing your ink properly, you have to stay up-to-date and maintain a current knowledge of federal, state and local regulations and ordinances. Ignorance of these requirements and the resultant penalties is no excuse, and an unacceptable defense. It’s just as important to make sure all your employees are aware that ink cannot just be poured down the drain or tossed in the garbage.
So what’s the proper way to dispose of your screen printing ink?
Safely Disposing Plastisol Screen Printing Ink
As plastisol inks are the most common in the industry, let’s start there first. Simply put, plastisol ink is a name for polyvinyl chloride (PVC) ink. PVC may contain phthalates. These are potentially toxic and are considered environmental hazards. As a result, many plastisol inks are now being manufactured phthalate-free.
When fully cured, plastisol ink absorbs the plasticizers in the ink. Depending on your location, fully cured plastisol ink (like on your printed shirts) may be disposed of in the local waste. Any uncured plastisol may be recyclable as a plastic if your community has such a program – but check first! Otherwise you’ll likely have to dispose of your ink through a licensed chemical waste disposal service, which can be pricey. Some chemical waste disposal companies offer classes on safe handling which might be helpful. If you use one of these companies, make sure they keep or provide you records of refuse pick-up. These would come in handy in case authorities have any questions. Make sure all your ink safety data sheets are in a binder and up-to-date. You’ll want to be sure you’re 100% compliant with the law.
Some screen printing shops help control waste by using an ink mixing system. This makes it easier for you to prepare only the amount of ink required for an order. As you only make what you need, the amount requiring disposal may be reduced. Leftover ink can be used later or combined with other remainder ink and black pigment to make a spot color black.
Taking Care of Water Based Waste
Water based inks, despite their eco-friendly name, may also require special handling. The pigment or binders in some of these inks may contain formaldehyde, oil or alcohol as well as other chemical solvents. Depending on concentration, these chemicals are often classified as hazardous. Some localities may accept an amount of disposable volume after a period of evaporation, as in an almost empty container of water based ink (formaldehyde would likely not be included).
The same disposal considerations must be taken when disposing of any ancillary items that have come in direct contat with your ink, including mixing sticks and cleaning cloths.
Looking for some tips on safely storing your ink for maximum performance and shelf life? Check out this blog post:
Interested in learning some more ways to make your screen printing shop more eco-friendly? Here are some ideas