Workplace chemicals and the role of the MSDS
The material safety data sheet is a helpful guide to determining the degree of hazard of common chemicals.
The material safety data sheet is a helpful guide to determining the degree of hazard of common chemicals.
John M. Fee
American Polywater Corp.
Avoiding exposure to hazardous chemicals in our daily lives is almost impossible because routine tasks like putting gasoline in the car, washing the dishes, and painting the porch involve chemicals that are hazardous. In cabling work, we may be exposed to cable and electronic cleaners, duct and fire blocks, oils, greases, encapsulants, adhesives, sealants, paints, and much more.
While it is not possible to avoid chemicals in our workplace, we should use them carefully to avoid any risk of injury to others and ourselves. The material safety data sheet (MSDS) is a key document that identifies hazards and helps us develop safe-use methods. In fact, the Occupational Safety and Health Administration`s (OSHA`s) HazMat regulations require that you have an MSDS readily available for any chemical you use in the workplace. Although the MSDS may contain ominous-sounding jargon, we still need it as well as other resources to identify chemical hazards and develop safe-use procedures.
Physical versus toxicological hazards
The MSDS gives us information on two different types of hazards: physical and toxicological. Physical hazards include properties such as flammability, stability, chemical incompatibilities, and corrosiveness. Toxicological hazards involve the effect of the chemical on the human body. Is the material toxic or poisonous to people? If so, in what way and at what levels?
Physical hazards involve how we handle the chemical and the surrounding environment. Warnings like "Do not use near fire and flame" or "Do not store in metal container" relate to physical hazards.
Toxicological hazards relate to our personal contact with the chemical. Warnings like "Wash hands before eating or smoking," "Use with adequate ventilation," or "Wear impervious gloves to prevent skin contact" relate to toxicological hazards.
The first place to find out about a chemical is on its label, which will have warnings about any significant hazards from the material. Besides precautions, the label may recommend protective equipment and first-aid information.
OSHA regulates the proper labeling of chemicals. While it is accepted practice to buy chemicals in bulk and repackage them into smaller containers for field use, you must properly label the secondary containers. Do not store or transport chemicals in unlabeled containers.
A type of hazard warning that you often see on bulk containers is the HMIG (hazardous material identification guide) label, which has four boxes--blue, red, yellow, and white--each with a number from 1 to 4 in them. Each color identifies a type of hazard with the number identifying the severity. The blue is health, red is flammability, yellow is reactivity (explosiveness), and white contains symbols for recommended protective equipment. If you are using any chemical with a 2 or above in any of the colored areas, you should be familiar with the details of the particular hazard that causes the rating.
Based on government health and safety regulations over the last few decades, the MSDS has become the primary document used to communicate safety information on chemical products. Unfortunately, these documents are often written with information for both the layman user and the physician. Additionally, environmental information not related to personal safety must also be put in the MSDS. Finally, the MSDS is often written to cover every level of contact from the expected to the extreme. The MSDS has become long, complex, and difficult for the layman to understand. Even so, it contains very useful information, and you should become familiar with its organization and content.
An MSDS can be obtained from the chemical manufacturer or distributor. You are not required to have an MSDS for consumer products used in the workplace for the same purpose as consumer use. However, it is good procedure to have an MSDS for all the workplace chemicals you use. It can avoid debate during an OSHA inspection. Walk the shop on a regular basis to see which chemicals are being used, and use this information to keep your MSDS files up-to-date.
A chemical is not hazardous just because it has an MSDS. American Polywater Corp. (Stillwater, MN) manufactures water-based cable-pulling lubricants. These are nontoxic and have no physical hazards other than being slippery if spilled on a hard floor. Yet, we still supply an MSDS for each type, even though these lubricants are probably less toxic than hair shampoo.
The first section you usually see on an MSDS is the hazardous-ingredient section. While interesting, this section is often not the most helpful. OSHA requires MSDS writers to report any hazardous ingredient that is a component of a mixture, even a low-level component. So unless you are familiar with the properties of the specific ingredient, you don`t know what its listing means.
As an example, anhydrous isopropyl alcohol--or isopropanol--is used to clean optical fiber before splicing it. If we review isopropanol`s MSDS, we see that 100% isopropanol is not highly toxic, but it can be irritating to the eyes, nose, and throat when too much of it gets into the air. We conclude the primary hazard of isopropanol is that it is quite flammable, with a flash point around 50oF and a "4" on the HMIG flammability rating.
If we were to use isopropanol by the drum to clean fiber- optic cable, we would need to be very careful to prevent sparks by grounding the drum. But since only a small quantity of isopropanol is typically used to clean a fiber, we can address the issue by using one of the presoaked wiping pads commercially available. The small amount of solvent minimizes any fire hazard.
Let`s contrast the MSDS of straight isopropanol against the MSDS of a window glass cleaner that contains 3% isopropanol. The MSDS would look similar with isopropanol reported as a hazardous ingredient (at 3%). Only by completely reviewing the MSDS would we conclude that the glass cleaner doesn`t really have a combustion hazard and that it`s safe to atomize it while cleaning windows.
The hazard identification section of the MSDS is a good section for initial analysis. American Polywater uses the HMIG system in the hazard-identification section on its MSDSs. Some use only narrative to identify hazards. Regardless of the method, this section will identify the main hazards of the material, if it has any.
One frequent problem with hazard identification is the "degree" issue. The MSDS may try to cover all levels of exposure, including excess to the point of being ridiculous. Water and table salt can both kill you, but not in the way you use them at the dinner table.
Try to relate your specific hazard to the way that you use the material. For example, an MSDS for isopropanol would probably state that continuous skin exposure would be irritating and cause defatting and redness. Yet, isopropanol is the same material (mixed with water) the doctor uses to clean and sterilize skin before an injection. That`s not excessive skin exposure, nor is the incidental contact during the cleaning of a fiber.
Several sections--fire and explosion, reactivity, and the health hazard--on an MSDS provide more-detailed information on any hazards identified.
The health-hazard section focuses on interaction with the human body, both short- and long-term. The MSDS will cover everything from occasional use to continuous contact and exposure.
To understand this section, you should know that there are three primary routes of entry that a material can take into the body. These are ingestion, inhalation, and via skin contact. Eye contact is often broken out as well, not so much as an entry route, but more as a critical, sensitive, and exposed organ.
Skin contact and ingestion are the easiest to address with proper procedures and protective gear. The more difficult exposure is inhalation. Inhalation is a potential exposure for any chemical that is a gas or evaporates into the air and can thus enter the body through the breathing passages and lungs. Materials posing such hazards include the solvent base of paints, adhesives, cleaners, and similar substances. "Acceptable" exposure levels for such airborne materials have been determined and are presented as threshold-limit values (TLVs).
Airborne chemicals and TLVs
Because airborne inhalation is such a common industrial exposure, hygiene groups and government agencies, including OSHA, have developed airborne exposure limits called TLVs or permissible exposure limits (PELs). These exposure limits are expressed in ppm (parts per million [in air] or pphm (parts per hundred million [in air]). TLVs represent the maximum recommended airborne concentration under which an average person can work for an eight-hour day without adverse health effects--in the opinion of health experts or the government.
With some very common chemicals, short-term exposure limits may be recommended. Such short-term exposure limits are usually somewhat higher than the TLV for the same material.
The biggest problem with a TLV is that it doesn`t mean much to the average person. Nor are there easy ways to know when a material is present in the workplace air above its TLV, unless the material has a strong odor that is detectable at or below the TLV, neither of which is the case for many materials.
The most practical way to ensure that air levels stay below the TLV is to ensure adequate or even excess ventilation, which causes both dilution and dispersion. It is also beneficial to minimize the amount of volatile material used so that the quantity released into the air is minimal.
But what if you have to use significant quantities of volatile materials in small, closed-in areas where ventilation is not practical? Then you must use the protective equipment-- usually a mask with an organic vapor canister or self-contained breathing apparatus--recommended in the control-measures section of the MSDS. You can bring in an industrial hygiene consultant to take air-concentration measurements when there is doubt on exposure levels for any operation. Just don`t ignore the inhalation exposure of airborne materials.
This section of the MSDS makes recommendations on how to control exposure and may address everything from occasional contact to continuous exposure. Control measures include gloves, goggles, vapor masks, and forced ventilation, depending on the hazard.
Realistically, highly toxic or extremely hazardous materials are not accepted or used in construction or maintenance. The control-measures section of the MSDS recommends good and practical precautions. One area requiring close attention is recommended eye protection. Proper eye protection is too often ignored with both chemical and mechanical exposures.
The first-aid section of the MSDS is an area that you hope you`ll never need. Regardless, you should review its content, especially to note any special materials such as eyewashes that you might want to have available at the job site.
Everything about safe chemical use and MSDS analysis could not be covered here. Industrial hygienists should be consulted on specific problems or questions.
You have seen how to find the data on an MSDS and use it to assess a workplace chemical`s hazards. Review your MSDSs on a regular basis and keep your files up-to-date. That is a good start to a safe workplace.
Bulk containers of chemicals should include an HMIG label with numbers in the circles indicating the degree of hazard the chemical poses.
The hazards listed on an HMIG label can be further detailed. This information can be included in an MSDS.
John M. Fee is president of American Polywater Corp. (Stillwater, MN) and can be contacted at tel: (800) 328-9384 or at www. polywater.com.