Choosing the Right Cleaning Chemistries

Q. Parts cleaning is critical to ensure our components are ready for the next stage in the process, but with changing regulations and worker safety a No. 1 priority, how do we make the right choice when it comes to cleaning chemistries?

A. There are many factors to consider in critical cleaning. Does the precision cleaning fluid clean well, does it do the job quickly, is it economically viable, does it meet regulatory requirements and environmental issues and, importantly, is it safe for workers?

Some cleaning methods used may work well to remove the contaminant, but they are not always the safest for staff. There are, however, cleaning chemistries out there that do put safety first, while providing all the other important qualities required of a great cleaner.

It’s All in the Numbers

When it comes to worker safety, it is important to look at the key features of a cleaning chemistry from corrosivity and flammability to toxicity. The risk of fire and corrosiveness may be well-understood, but toxicity can appear more difficult to figure out. Determining a cleaner’s ability to do the job well against its toxicity risk is an important aspect to consider. One way to understand toxicity is to look at Section 2, Hazard Identification, and Section 8, Exposure Controls, of the cleaning product’s Safety Data Sheet (SDS).

Section 2 details if OSHA regulates a product as hazardous, and what type of physical and health hazards are associated with the product. The exposure limits detailed in Section 8 are to safeguard workers from exposure to high levels of chemicals that can be dangerous, whether that is through short-term use or during their working life. First, look at the toxicity ratings detailed in the SDS. There are several names associated with these ratings; perhaps the most common is TWA (Time Weighted Average), but they can also be listed as PEL (Personal Exposure Limit) as generated by some manufacturers, as well as AEL (Allowable Exposure Limit), which are assigned by a government body.

Expressed in parts-per-million (ppm), it helps to evaluate if a cleaning chemistry can safely be used in the workplace. These values may also be specified in milligrams per cubic meter (mg/m³) or milligrams per liter (mg/l). A greater number is better, as it specifies that a larger concentration of exposure can take place without causing adverse effects. Higher numbers, those approaching 1,000 ppm, which is the highest rating possible, indicate a safe chemistry. The lower the score, the greater the risk of exposure.

The scores are estimated by the calculation of a worker’s risk from exposure to the cleaning chemistry for a typical work week—eight hours per day, five days a week—over a theoretical 30-year working career. A lower score indicates that even short-lived contact with the chemical can be hazardous. If a cleaning solution has a TWA of less than 25 ppm, extra engineering controls such as personal protection equipment, ventilation and air filtration, along with air-quality monitoring, may be needed to ensure worker exposures are maintained below the exposure limits.  

Fluids, cleaners or coatings with a TWA of 50-100 ppm can be used safely, but only with implementation of the correct equipment and training. Fluids with a TWA of 100-200 ppm or more are better still. Although the potential for concern is manageable, they may still require engineering controls to ensure exposures are kept below the exposure limits

Exposure limits are “time-weighted” and are designed to manage worker exposures on a daily basis that may last days, weeks or even years. It is prudent to understand the underlying basis for exposure limits recommended or mandated by an organization or vendor. Some exposure limits are set simply to prevent acute effects that could make working uncomfortable or difficult to perform. Other exposure limits are set to prevent more serious and immediate effects, further quantifying the risk of using a specific chemical.

Don’t be Risk Averse

It is not only TWA values that help to measure the safety of the chemistry; also look at vapor pressure, which can be found in Section 9 of the product’s SDS. If a vapor pressure is known and applicable, it will be included in the SDS. A fluid with a high vapor pressure will volatilize easily and readily generate vapor. This is especially apparent within small enclosed spaces. Also, if this vapor is flammable, the threat of fire can be high. As a best bet, always choose a cleaner with low vapor pressure; not only will it reduce the flammability risk, but it will also lower the hazard of inhalation exposure.

Before deciding on a cleaning solution, it is essential to obtain as much information as possible concerning the identity of the chemical or chemicals of the product being used. To reduce risk to workers, understand and consider all the figures on the SDS. This significant piece of information will offer specific details on the product’s potential hazards and allow users to understand the potential threats helping to make an informed decision.

Look at the Whole Picture

All cleaning chemistries will have an SDS organized into several categories such as identification of the substance and manufacturer, toxicological information, and exposure controls/personal protection. It is important to remember that concentrating on just the TWA figure is insufficient for a comprehensive assessment. Look at the whole picture to determine safety. Fundamental aspects to consider include flammability, storage, handling and disposal. All of these details need to be included in any safety analysis.

Innovative cleaning chemistries have been developed to not only work effectively to remove the contaminant, but which also address worker safety, regulatory requirements and environmental concerns. Before selecting any cleaning solution, contact the cleaning chemistry manufacturer. They will have the knowledge and experience to answer any concerns and can recommend cleaning solutions that do the job well without any safety implications.

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Mike Jones is vice president of MicroCare. Visit microcare.com.