Solvent printers and air quality control

As the printing world has evolved, so too has the advent of the solvent based wide format printing system.  Printing operations of all sizes are recognizing the value of adding these types of printing systems to their production lineups, enabling them to offer new and old customers alike a wider range of printed products.  Vehicle wraps and outdoor signage, just to name two, are rapidly expanding market places, and with that comes the continued reliance on the solvent based printers for providing prints that will stand up to the sometimes extreme conditions that mother nature can throw at us.  For all those who have hypothesized that the emergence of the UV flatbed printer would displace the need for the solvent based printer, you have underestimated the strength of the solvent based printer.  And if sales volumes of current models and the introduction of new brand names are any indication of the strength of the marketplace, solvent printers are here to stay.

It is no secret that shops running solvent based wide format printers experience a level of fumes and odors that can cause health concerns and discomfort for employees and customers alike.  Many shop owners describe themselves as having become desensitized to the smells, but often concede that customers entering their store react surprised and respond with “how can you work all day with that smell”?  As well, new employees will complain of headaches, dry mouth, and sinus trouble until they eventually become desensitized as well, if not ill to the point of needing medical intervention or simply quitting due to the hostile working environment.

For years it has been accepted that these operating conditions are par for the course and accepted as normal, but we have come to a turning point where these fumes and odors are more than just a nuisance, they pose real health concerns.  Whether you are running an eco-solvent printer, a wide format printer (up to 3 meters wide), or a grand format printer (over 3 meters wide) these concerns are dangerously real and present.  Therefore, shop owners need to be properly educated as to the effects of exposure to these fumes and odors, as well as preventative measures to provide employees with a safe and healthy working environment.  The shop owner needs not only to protect his or her employees’ health, but they need to protect themselves from liability as well.

It is important to note here that just because there is a really bad fume or odor smell in a working environment doesn’t necessarily mean there is a hazardous contaminant present, and that just because you can’t smell something bad doesn’t necessarily mean there is no hazardous contaminant present.  While often the two go hand in hand, and the presence of one can indicate presence of the other, a shop owner should not simply assume they are both present or not. Providing a safe and healthy environment is achievable, but before we can address the solutions to reducing or eliminating health concerns caused by overexposure to airborne contaminants, we need to have a better understanding of exactly what the problem is.

The process of solvent based printing is simple: a solvent component mixes with the ink and carries it to the media and is printed onto the same media.  The solvent then evaporates off of the media leaving the ink behind to produce a print.  This is where the problem begins.  The evaporated solvent product has been deemed hazardous for human consumption when found in high concentration levels.

The fumes and odors that you are smelling are called VOCs (Volatile Organic Compounds), and these VOCs are regulated by the government based organization OSHA (Occupational Safety & Health Administration).  For many of the compounds found in most solvent printers, exposure limits for humans have been set as low as 20ppm (parts per million).  Often information on the allowable exposure limits can be found in the Material Safety Data Sheet of the ink, which should be provided to you by the dealer or manufacturer when you purchase a solvent based printer.  The allowable exposure limit of any given chemical is very important for shop owners to know because if an employee becomes ill or suffers health problems as a consequence of overexposure to these VOCs the shop owner can be held liable for medical expenses, workers’ compensation claims, or possibly subject to fines by OSHA for non-compliance.

Understanding VOCs, ppm, and allowable exposure limits is a complicated process involving lengthy mathematical equations, and it is a little much to expect the average shop owner to know all of the particular elements that can come into play.  Furthermore, simply knowing what the allowable exposure limit is doesn’t tell us whether a particular shop environment is compliant or not.  The human senses can detect that VOCs are present but can not discern the level at which they are present.

To know the level of VOCs that these machines produce, indoor air quality testing must be done.  I contacted many of the printer manufacturers directly to ask for data on the level of VOCs produced by their printers, and the typical answer was “there are too many variables to determine what concentration level may or may not be present when our printer is running.  It is ultimately the responsibility of the shop owner to ensure that he or she provides a safe and compliant working environment for his or her employees”.  As such, the printer manufacturers have been able to wash their hands of any responsibility regarding VOC exposure to the end user.  And while the manufacturer may be correct in its declaration, this unfortunately doesn’t help end users establish what they may or may not need to do to provide a clean and healthy working environment for their employees.  

In between the manufacturer and the end user lies the dealer, and most quality dealers will take the time to educate the end user about the need for adequate air filtration when employing a solvent based printer, as well as offer them proven and accepted solutions so the end user can make the best possible decision on how to provide his or her employees with the cleanest and safest working environment.  These dealers have taken the time and energy to educate themselves on available solutions, and as an end user I recommend that you utilize their knowledge and expertise on this issue.  In fact, I believe that a dealer should not be selling a solvent based printer with out offering an air filtration system with it, as well as taking the time to explain to customers why such a system is required.

Having said all of that, it is very impractical and costly for each end user to hire in an indoor air quality testing company to make sure they remain compliant, or to measure whether or not filtration is even required to meet compliance.  Realizing this hurdle to end users, Island Clean Air Inc. of Vancouver, BC, contracted an independent California State Certified air testing company to measure the concentration level of some of the most common printers on the market today, and the results were surprising.

Each test was conducted under what was to be considered an average operating environment of a room in size from 100 sqft (10’x10’) to 400 sqft (20’x20’), and the printers were run at average print speeds on full size media with a full gamut of colors. Each printer’s production speed was dependent upon the overall capacities of the individual printer.  Tested were the HP Designjet 9000s, Colorspan Gator 72s, Mimaki JV3-160, and the Mimaki JV5-160.  Each test was conducted at different locations on different days to avoid any cross contamination and ensure the objectivity of the results.  

For the initial testing, no means or air filtration or ventilation was emplo
yed, it was simply the printer running in a sealed room.  Interestingly, each printer, in its tested room size, surpassed the allowable exposure limit with in 30 minutes of print operation, with a measured range of between 20ppm and 200ppm, depending upon which printer was tested.  As production occurred past the 30 minute mark, this number continued to increase (see figure 1 and 2)—remember that the allowable exposure limit can be as low as 20ppm!”

These tests conclusively show that solvent based wide format printers are prone to creating an environment with higher than allowable exposure limits.  Therefore, shop owners can conclude that if you are running a wide format solvent based printer, you must provide some method of filtration or ventilation to ensure your employees are not put into a working environment where their health and safety may be at risk.  What a shop owner decides to provide for filtration/ventilation is their own prerogative, and is a point of debate amongst air filtration system manufacturers.  

Next month we’ll compare 4 available methods of VOC removal and analyze their pros and cons.
    
Larry Miller
Vice President
Island Clean Air, Inc.