Much was made of an article published in Neurology, the medical journal of the American Academy of Neurology – and for good reason.
It indicated that “industrial workers exposed to solvents have a much higher risk of suffering memory loss and poor cognitive health later in life.”
This study included over 2,000 retirees who had been exposed to a variety of solvents (Science Daily has a good summary and more detail if you’re interested).
Reasons to Reduce Solvent Use
If you’re reading this blog, chances are you’ve had some regular exposure to solvents. While the study does differentiate between those with high, moderate and limited exposure, we can only assume that none of us is getting off without at least minor consequences. My goal is not to be alarmist or to discuss the impacts of the exposure, but rather to ask those of you with decision-making and process change authority, “What are you doing about it?”
If the threat of diminished cognitive health (the ability to think, learn and remember) isn’t enough motivation to move solvent reduction up your company’s priority list, there are other good reasons to consider solvent reduction initiatives. The opportunity to eliminate wasteful spending on materials, waste treatment, and disposal is a great reason; even recycling or reusing solvents can reduce careless spending.
There are many approaches to solvent reduction, but due to your diminished cognitive health, you probably won’t remember them. To help, I have listed some places to look for opportunities.
Improved Materials
- Medium and high solids paints typically have a range of 40-70% solids and 30-60% volatile organic compounds (VOCs). Compare this with 20-40% solids for standard wet paints.
- Water-based paints have similar solids content to conventional paints, but with far fewer VOCs (typically 10-20%).
- Using premixed coatings can help you avoid mixing on site.
Improved Equipment
- When spraying, you might consider replacing your conventional spray gun with HVLP spray guns, if your process allows. These promote better control, better coverage of recesses, and typically offer efficiencies of 65-85%, as opposed to 50% with traditional spray guns.
- When using viscous coatings, consider using temperature control equipment that can produce the correct coating viscosity without excessive use of thinners.
- If your business uses higher-value coatings, you should consider using electrostatic spraying. The charged paint is attracted to the grounded piece and improves transfer efficiency. Combined with an HVLP spray gun, electrostatic spraying can achieve transfer efficiencies of 65-95%.
- Robotic paint sprayers often reduce coating use by 20-30% over manual spraying. Although expensive, robotic spraying has advantages for large and complex shapes because it offers high efficiencies, high quality, and reduced labor costs.
Improved Equipment
- Thinning or mixing coatings in a centralized mixing room (or preferably in an enclosed machine) helps contain solvent emissions.
- If practical, prohibit process owners from mixing their own coatings at the process. This can reduce unnecessary emissions in the workplace.
- Optimize spray gun settings and procedures for spray gun operators. This may require controlling material viscosity or temperature. Encourage them to maintain all settings unless they have permission to do otherwise.
- Control paint sprayer cleaning solvent use by providing operators with a set amount each day or each shift. Try using triggered spray containers rather than free access to cans.
Summing Up
None of this information is new, but it is important.
Many of you may already be doing several of these things, or perhaps have investigated them and determined that they’re not practical for your operation.
As I explained earlier, there are lots of smart reasons to consider solvent reduction initiatives. Preserving your ability to think, learn, and remember just became another one.