Prior to using any chemical, even if it is something you have worked with for years, you need to understand the hazards and how to work with it safely.
To understand the hazards, you first have to know what they are. How?
The first place to learn about chemical hazards is labels. There are many different types of labels. U.S. DOT (Department of Transportation) labels, HMIS (Hazardous Materials Identification System), NFPA (National Fire Protection Association) and product labels. Your company may apply their own labels once a product reaches your facility. Water Tech, Inc., product labels include warning statements, first aid information, spill information, handling information, as well as HMIS ratings and U.S. DOT information. Be aware of and familiarize yourself with the different types of labels, so you can quickly identify immediate hazards in your area. Labels are a wonderful tool, but, labels can only contain so much information. You will need to investigate further. The second place to check is a Material Safety Data Sheet (MSDS) or Safety Data Sheet (SDS). These sheets will have specific, detailed information on the chemical. Consider the MSDS/SDS as a type of encyclopedia entry on a chemical. It does not necessarily tell the whole story, but gives a more in-depth look. For example, the label may indicate that a chemical is flammable, but it does not reveal the flash point. The MSDS/SDS will give you the flash point, as well as additional information on the flammable properties and steps you can take to extinguish a fire involving this chemical. The MSDS/SDS is an informative document, but sometimes you need to dig a little deeper. The third place to check is with the manufacturer and/or distributor. Their employees can expand further on the information contained within the MSDS/SDS. The MSDS/SDS says to absorb the product in case of spill, but what kind of absorbent is recommended? Other resources include: the internet, the library, industry and association publications or even a local chemistry teacher or professor. If you utilize the internet, ensure you are using a well-known and respected source. Now that you know where to look for information, you need to know how to interpret it. You will see lots of terms in your research: physical hazards, reactive hazards, health hazards, toxicity—what does it all mean? Physical hazards are things like flammability and reactivity. These hazards are usually included on product labels and are generally easier to determine. A U.S. DOT flammable label or an HMIS or NFPA label with a high flammability rating will quickly tell you not to place a kerosene heater in the vicinity of this chemical. The detailed information in the MSDS/SDS will tell you the flash point, autoignition temperature and flammable limits, so you can properly store the chemical. Reactive hazards are also included in physical hazards. A reactive symbol or a U.S. DOT label with the words, “Do not mix with water,” or “do not mix with air” or “dangerous when wet” is your clue here. Seeing a number other than zero for the reactivity rating on an HMIS or NFPA label will also be a tip. However, not all reactive chemicals have labels. Labels are for immediate hazard information. The “dangerous when wet” wording informs you that the chemical should not be stored underneath the leaky part of the roof, but does not tell you if this chemical reacts with strong acids or alkalis. The MSDS/SDS should be checked thoroughly to determine reactive hazards. If you are mixing chemicals, you should thoroughly understand not only the reactive hazards of all chemicals involved, but also process safety management. Health hazards are often less clear than physical hazards, and are found in MSDS/SDS as opposed to on labels. Often, two terms are used interchangeably: TOXICITY and HAZARD, but they are actually very different.
- Toxicity: The ability of a substance to cause harm.
- Hazard: The likelihood that a material will cause harm under the conditions of use.
Using these definitions, we can say that with proper handling, even highly toxic chemicals can be used safely. Conversely, less toxic chemicals can be extremely hazardous if handled improperly. The actual health risk of a chemical depends on the toxicity and the actual exposure. No matter how toxic the material may be, there is little risk involved unless it enters the body. An assessment of the chemical’s toxicity and the possible routes of entry will help determine what protective measures should be taken. A substance that is toxic can also be described as poisonous. However, there are different types of toxic effects. Local toxic effects affect only the immediate area. For example, if you spill acid on your arm, the effect is on your arm. It does not spread to your central nervous system. Systemic toxic effects involve tissues or organs other than the contact site. For example, if you ingest methanol, it may cause blindness. Toxic effects can also be categorized as acute or chronic. An example of an acute toxic effect of ethanol is drunkenness. A chronic toxic effect of ethanol is cirrhosis of the liver. Acute effects are more immediate, and you can generally recover. Chronic effects generally are the result of repeated exposure over time. Chronic effects are delayed and can last over a period of time. Recovery is more difficult, or impossible, in some cases.
Common Routes of Entry: Skin Contact, Eye Contact, Inhalation, and Ingestion.
Skin contact is the easiest way for chemicals to enter the body. Skin contact may result in a local reaction, such as a burn or rash. Skin contact may also result in a systemic reaction, if the chemical is absorbed into the bloodstream. The health of skin plays an important role. Skin that is dry, cracked or has lacerations is less resistant to chemicals. Wear impervious gloves and protective clothing to minimize skin exposure. In the event your skin is exposed to a chemical, rinse the affected area with water for at least 15 minutes, removing clothing if necessary. Seek medical attention if symptoms persist. Eye contact with chemicals is especially dangerous. It can result in painful injury or even blindness. Wearing safety goggles or a face shield can reduce the risk of eye contact. In the event your eyes are exposed to a chemical, rinse eyes immediately with water continuously for at least 15 minutes. Remove contact lenses if they are present. Seek medical attention if symptoms persist. Inhalation is a common route of entry for gases, vapors and particles. These substances may harm tissue or enter into the bloodstream and can cause irritation of mucous membranes. Most chemicals do have an odor that is perceptible at a certain concentration. Olfactory fatigue may occur when exposed to high concentrations or after prolonged exposure. This may cause the odor to seem to diminish or disappear, while the danger remains. Chemicals that produce vapors should be used only in well-ventilated areas. If ventilation is not adequate, use a respirator. If a respirator is needed, your employer should have a complete respiratory protection program that complies with 29 CFR 1910.134. In the event of inhalation exposure, increase ventilation by opening windows or doors, close containers and move to fresh air. Seek medical attention if symptoms persist. Ingestion is a possible route, but less likely than skin or eye contact or even inhalation. Ingestion may occur if you eat or drink contaminated food and beverages or by touching your mouth with contaminated hands. You can reduce the likelihood of ingestion exposure by wearing gloves and not eating or drinking while working with chemicals. Do not store food or drink in the same areas where chemicals are stored. Wash hands thoroughly after working with chemicals and prior to eating, drinking or smoking. In the event of ingestion exposure, contact the Poison Control Center at 1-800-962-1253 for instructions or see a health care professional immediately.