Most manufactured objects require chemicals during build and assembly processes. In nearly all instances, workers handle chemicals. As critical cleaning consultants, we frequently observe chemical use during cleaning operations. We see a wide range of practices when it comes to handling chemicals – some of those practices are problematic.
No company wants to be in the headlines because of a toxic spill, or to be subjected to fines and lawsuits. What we think of as safety encompasses exposure of workers directly involved in using the chemicals, or storing them, or moving them in and out of cleaning equipment, or transporting them, or even arranging them to be transported. Chemical safety issues also impacts people within the manufacturing plant, like office staff, who may not work with chemicals but may be inadvertently exposed to chemicals. Chemical safety is important to the neighborhood right near the plant, to the city, the region, the nation, and the entire planet.
The devil we know
Some chemicals are considered to be particularly dangerous. They may be immediately dangerous – for example, they may catch fire when exposed to air. There may have been scientific studies indicating short or long-term toxicity. Insurance companies may be concerned with avoiding damage to employees, to company assets, and even to surrounding neighborhoods. Your legal department may become proactively concerned. The chemicals may have come under the scrutiny of governmental agencies. In the U.S., this means agencies like OSHA (concerned with worker safety) and/or the EPA (primarily concerned with environmental issues).
Because the dangers and the consequences of improper handling are well-defined, in a sense such chemicals may be easier to handle safely. They MUST be handled very safely or the result has dire consequences to the health of the worker or the pocketbook of the manufacturer. There may be “cookbook” methods to handle such chemicals safely. Elaborate processes and training programs are designed to safely handle these materials.
Solvent Substitution
The concept of solvent substitution is an axiom among safety and environmental professionals. The concept of solvent substitution is that if you eliminate a chemical perceived as dangerous and instead use one that is safer, you protect workers, the neighborhood, and the environment. Makes sense, no? Well, maybe. We are in favor of solvent substitution, all other factors being equal.
However, in solvent substitution programs, it is important to look at the whole picture. All other factors are usually not equal.
It’s the process – not just the solvent
Chemicals used in critical cleaning and in other manufacturing activities are generally used in a process; the way the chemical behaves in the process can influence whether the substitution makes for greater safety. Smart manufacturers ought to think in terms of PROCESS SUBSTITUTION, not simply SOLVENT SUBSTITUTION.
If the cleaning performance of the substituting chemical is inferior to the original, more of it may be needed to accomplish the cleaning task. Is this really an improvement? Well, regulators may decree that it IS an improvement; but you have to consider the impact on hazardous waste streams and employees exposure – this may involve training the people. Perhaps to get the job done, a higher pressure spray or higher temperature is needed. We sometimes observe situations where a very high pressure spray can potentially injure employees. Safety concerns with both pressure and temperature may offset the presumed safety advantages of solvent substitution.
The devil we don’t know
No chemical or process is completely safe. Many chemicals that are considered ‘safe’ or at least ‘safer,’ because they have not been used as widely in industry, because fewer toxicity studies have been performed, because their have been no industrial accidents (yet), because regulators have not noticed them, or because producers of competing chemicals have not yet engaged in negative lobbying to regulatory agencies (aka political chemistry or sniping). Sometimes, success of a chemical or blend breeds regulation. The, we’re on to the next “flavor of the month” chemical syndrone.
In some cases, the substitution is with a chemical that has not undergone as much toxicity or environmental impact testing as the one you are attempting to replace. A statement like ‘ worker exposure studies not available’ does not mean that the substance can be used without safety or environmental controls.
Safer processes
Too many people in the manufacturing and regulatory world are convinced that almost all organic solvents are inherently hazardous and that almost all water-based chemicals are safe. In reality, both classes contain risks and both classes can be handled safely. Most chemicals can be handled safely. Conversely, with the IMPROPER creativity and lack of planning, almost any chemical can be handled unsafely.
Let’s start with water. It’s pretty safe – we drink it; we bathe in it. If you have a large manufacturing process using a large tank of room temperature water at the shop floor level, without guard rails, people can slip and fall in. Should we put up a sign like “complete, prolonged immersion in this chemical can result in acute respiratory distress and may be fatal?” You certainly need engineering controls and the right training. If the water is hot, in a large or small tank, it can burn people. Again, you need engineering controls, employee protection, and training.
Aqueous cleaning formulations contain additive chemicals to enhance cleaning efficacy. These are to change the pH, lower surface tension, help soils to dissolve, discourage foaming, or to provide other properties that water alone does not have. These additives can be hazardous. Both acid and alkaline agents can pose significant risk if they contact the worker. Neutral formulations may contain skin irritants or promote bacterial growth. Consider the impact of the process; be sure there is appropriate training.
Let us be perfectly clear. Manufacturing processes where employees squirt perchloroethylene (or any other chemical) up their nose are unacceptable. Situations where employees inadvertently squirt any chemical (even a safer chemical) up their nose are also unacceptable. Many solvent cleaning processes can be accomplished in a small, enclosed apparatus, where risks to both workers and the external environment are minimized. If the solvent is effective for cleaning, very little may be needed. In our experience it is beneficial in terms of safety, environmental protection, and product safety, to use all cleaning agents – aqueous and solvent – in relatively contained cleaning processes.
Flammability
Solvent substitution means using a flammable or combustible solvent. For example, acetone is highly flammable; and it is very popular in solvent substitution programs because it has a favorable worker safety profile and is usually not treated as a VOC. Sometimes, the cleaning agent you start with may not pose as much of an initial hazard, but it may react or degrade to form a flammable or combustible material. Esters can hydrolyze to form acids and alcohols. You can avoid headaches by having a qualified safety professional partner with your engineering and production staff. Factors include choosing the correct cleaning equipment, installing and maintaining it correctly, and looking at the location of nearby processes in terms of chemical compatibility and ignition sources.
Handling all chemicals
Any chemical, whether considered to be hazardous or safe, needs to handled with respect. Does that mean that full body protective gear needs to be worn for all chemical operations? Of course not! But we usually recommend that workers at least wear gloves for most, if not all operations, even those that do not use chemicals. They protect both the worker and the product. For instance, contamination from fingerprints is one of the leading reasons that products need to be cleaned during build and assembly. And cleaning usually employs chemicals, so more cleaning just increases the risks from chemical handling.
Education
We have alluded to employee training. HAZMAT training is mandated for workers who handle hazardous chemicals. Training is required and necessary – it’s not enough. We recommend that you also educate employees about the safe management of chemicals in your manufacturing facility, with your specific mix of manufacturing processes. In the feature article in the January, 2015 issue of Clean Source, we discussed the value of having an educated workforce. It should include the handling of ALL materials, whether considered hazardous or not. The worker should understand the process they are working on and why and how a particular chemical or chemical formulation is used. This may include a bit of practical chemical education. For most manufacturing facilities, we suggest ongoing, regular programs, beyond what is mandated.
