Army Research Lab
Adelphi Lab Center
Many chemicals that at one point were used frequently with little concern were later found to be toxic. Some even resulted in long-term effects on those who were exposed to them. But how do we identify chemicals that still haven’t been studied enough to prove to be the cause of disease, much less implement controls for them?
There are numerous examples of chemicals and metals that were once used but have since been banned after studies and reports of adverse effects were brought to the public. For instance, mercury. A household thermometer contained about one gram of mercury. One gram can contaminate a 20-acre body of water enough to cause a public advisory against eating fish from that water. Mercury is toxic and affects the nervous system, especially posing danger to pregnant women and young children.
Lead is another example. Lead is a naturally occurring metal that was widely used in a variety of products, including paint, pipes, ceramics and even cosmetics. The United States banned the manufacture of lead-based paint in 1978 and restricted the lead content of solders, faucets and pipes in 1986.
Currently, there are many organic solvents being studied for having a link to reproductive problems, including miscarriages, birth defects and low birth weights. A lot of these solvents are extremely prevalent in laboratory work and manufacturing plants and can be found in many household paints and paint thinners. As studies and risk evaluations continue, some current recommendations are to decrease permissible exposure limits (PELs) to these solvents.
When there are discrepancies in guidance of the recommended time weighted average (TWA), it is understandable to have concerns. Nanotechnology and the use of nanomaterials is another new technology that has brought a lot of questions with regard to the potential for toxicity and long-term prevalence in the environment. One way of better understanding the hazards of any chemical being used in a workplace setting is by reading the Safety Data Sheet (SDS). An SDS should be easily accessible by every worker for every hazardous material and chemical utilized. By learning how to read an SDS, you can protect yourself and others.
Every SDS is written using the same template to allow the user to easily locate pertinent information. The SDS is part of the Globally Harmonized System (GHS) to allow for the material’s hazards to be translated worldwide, across different nations and languages. For example, the pictograms and SDS will be written the same way whether you acquire a chemical from Thailand or from Brazil. Section 2 of an SDS is where the material’s hazards and precautionary statements are listed. Section 4 lists first aid measures, and Section 8.1 is where the TWA and PEL can be found.
However, this article is about newer materials in which the adverse effects or appropriate TWA may not be known or adequately studied, thus not accurately listed. In situations like this, concerns should be brought to safety personnel onsite to discuss ways to monitor, assess and report use and exposure levels of these materials. There are multiple ways to conduct air sampling for both short- and long-term exposure. Once the contaminant has been identified, the most appropriate analytic method can be searched for within the National Institute for Occupational Safety & Health (NIOSH) Manual of Analytic Methods (NMAM) at the Centers for Disease Control and Prevention at https://www.cdc.gov/niosh/nmam/.
If you or someone in your workplace is experiencing any of the following symptoms, look for possible sources that have not been identified, thus properly controlled. It could be that a material that is being handled or used frequently in an operation has been underestimated. Symptoms could include dizziness, headache, irritated or scratchy eyes or skin, rash, nausea, vomiting, diarrhea, sneezing, coughing, sore throat, nervousness, irritability, tremors, loss of balance or coordination, or reproductive issues such as low sperm count for men or irregularities in menstrual cycle, damage to fetus, or even miscarriages in women.
Sometimes, chemicals that have long-term adverse effects will not show any symptoms right away but could still be threatening the health of those working with or around them. Promoting awareness and open dialogue is the first and most important step in managing and reducing these potential risks. Safety and occupational health managers can then proactively look for controls such as ventilation, chemical fume hoods and personal protective equipment to use while the substance in question is further investigated.
- Bertot, E, et al. Models and Mechanisms of Public Health. Exposure to Unknown Hazards | Models and Mechanisms of Public Health (lumenlearning.com).
- Chester County. The Dangers of Mercury Thermometers | Chester County, PA - Official Website (chesco.org).
- National Institute of Environmental Health Sciences. (2020, November 25). Lead (nih.gov)
- National Institute for Occupational Safety and Health. (2018, September 20). CDC - NIOSH Publications and Products - NIOSH Manual of Analytical Methods (2014-151)