Workers in industrial manufacturing plants, lab technicians, storage facilities, and on many construction sites handle potentially hazardous materials (or “HAZMAT”) every day. Explosives, known carcinogens, and radioactive substances are widely-used, and often deemed necessary, in many industries.
Hazard Communication (sometimes shorted to “Hazcom”) is the Occupational Safety & Health Administration‘s way of ensuring that workers who must work with dangerous substances are properly informed of a materials’ hazards and know how to safely work with them.
Explaining OSHA’s Hazard Communication Standard
OSHA’s Hazard Communication Standard is set out in the Code of Federal Regulations 1910.1200. In other words, it’s a federal law intended to protect all workers and their right to know which materials they are working with and what dangers those materials present.
The law defines a set of legal responsibilities that cover both manufacturers of chemicals and the employers who use them.
A Manufacturer’s Responsibility
Companies that produce chemical substances, along with those who import them from overseas, are required to evaluate their materials for hazards. If any dangers become apparent, manufacturers must make this fact known by:
- Labeling shipping containers, drums and barrels with warnings
- Providing safety data sheets (SDS) along with their products
SDS used to be called “material safety data sheets,” or MSDS, but OSHA decided to change the name in 2012, when it revised the Hazcom Standard. OSHA made the data sheets more “user-friendly,” and the information is broken into 16 sections.
How To Read A Safety Data Sheet
Section 1 identifies the chemical, lists its recommended uses, and provides contact information for the supplier. If there are ways in which you should definitely not use the product, they’ll be listed here.
Section 2 identifies the chemical’s hazards. This is probably the most important part of the Safety Data Sheet, so we’ll break it down.
1. The material will be put in a category, in line with the Globally Harmonized System (GHS). The GHS presents a standard way of classifying chemicals and their hazards that is supposed to be used by every country. It’s just a guideline, though, so countries that don’t use it aren’t doing anything illegal under international law.
On a label for gasoline, you might find classifications like:
- “Flammable Liquid — Category 1”
- “Aspiration Hazard — Category 1”
- “Carcinogenicity — Category 1”
Each classification defines a different type of hazard that gasoline presents. First, gasoline is “flammable,” it catches fire at temperatures less than 93° Celsius (gasoline’s flashpoint is actually around -43° C). Next, gasoline is dangerous when “aspirated,” or ingested directly through the mouth or nose. Finally, gasoline is a “carcinogen,” it has been found to cause or increase the risk of cancer.
Every hazard classification will be followed by a Category number. This is a scale from 1 to 5 that tells you how dangerous a chemical is in relation to other substances. 1 represents the most dangerous and 5 is the least.
2. Then there will be a “signal word.” There are only two:
- “Danger” for severe hazards
- “Warning” for less severe hazards
3. Next comes the “hazard statement.” This part simply describes the danger in clear terms, like:
- “Extremely flammable liquid and vapor”
- “Fatal if swallowed”
- “Toxic if swallowed”
- “Harmful if swallowed”
4. Next you’ll find symbols (“pictograms”) that represent each type of hazard. For flammability, there will be a little picture of a fire. For environmental hazards, there will be a little tree. For acute toxicity, chemicals that can kill you in small doses, there’s a skull and cross bones.
5. Below the pictogram, you’ll find precautionary statements. This section outlines the ways you can minimize a substance’s hazards.
For example, you might find:
“Do not store near heat, sparks or open flames. No smoking. Wear gloves, eye protection and other personal protective equipment during use.”
Section 3 gives a detailed description of the material’s chemical composition.
Section 4 provides first-aid information if a worker is exposed to the material. This section is written for untrained responders, generally other workers, and the steps should be followed immediately. These are things you should do while you’re waiting for EMTs to arrive.
It will also include symptoms of exposure, so you can “diagnose” another person if you need to know whether or not they’ve been exposed.
Section 5 gives you instructions on fighting fires caused by the material. It also includes information for fire fighters, who may need to wear special gear when dealing with the fire.
Section 6 tells you what to do if the material is accidentally spilled or leaks. There are specific ways you have to contain or clean-up different hazardous chemicals.
Section 7 provides information on how to properly store and handle the material.
Section 8 describes exposure limits (what concentration of the material you can be exposed to without being harmed), engineering controls (like using a ventilation system in areas where the material is being used) and the appropriate personal protective equipment to wear around it.
Section 9 lists the physical properties of the hazardous material. It will tell you what the substance looks and smells like, so you can identify it, along with its pH, flash point and other chemical properties.
Section 10 describes the substance’s reactivity, explaining whether or not the chemical can react dangerously with other materials or under certain environmental conditions.
Section 11 explains the material’s toxicology. In other words, it describes the possible ways you can become exposed to the substance and what happens if you are. Immediate symptoms and chronic effects are all listed here.
Section 12 gives you information on the chemical’s environmental effect. If none have been identified, you won’t see section 12 on your safety data sheet.
Section 13 tells you how to dispose of the hazardous material properly.
Section 14 explains how the substance should be transported over long distances.
Section 15 describes any particular regulations that the material may be subject to.
Section 16 provides additional information that doesn’t fit in any of the other categories.
An Employer’s Responsibility
Employers are responsible for:
- ensuring that containers are properly labeled
- keeping safety data sheets easily accessible for employees
- conducting training programs for all employees who work with hazardous materials
Types Of Hazardous Materials
Materials can be defined as being either “health hazards,” “physical hazards,” “environmental hazards” or a combination.
Hazcom Physical Hazards
“Physical hazards” may not be dangerous in and of themselves, but are able to ignite, burn or explode under certain conditions.
- Explosives, like nitroglycerin, that can produce gases at such extreme temperatures and pressures that they explode.
- Flammable gases, like butane, that can ignite in the air.
- Flammable aerosols, canisters that contain at least one flammable ingredient.
- Oxidizing gases, like chlorine and fluorine, produce oxygen of their own accord. This makes the air more flammable than it usually is, but oxidizing gases do not burn themselves.
- Gases under pressure, hydrogen is a common example, are held in pressurized canisters. Sudden releases of this pressure may cause physical harm, and canisters may explode when frozen.
- Flammable liquids, like acetone and dimethyl ether, are liquids that can catch fire.
- Flammable solids, like camphor and aluminum powder, are easily combustible.
- Self-reactive substances, like hydrazine-trinitromethane, are highly unstable and can produce extreme amounts of heat in the absence of oxygen.
- Pyrophoric liquids, like tert-butyllithium (often packaged in ethyl ether), can ignite spontaneously within 5 minutes of being exposed to air, even in small quantities.
- Pyrophoric solids, like lithium, ignite under similar conditions as pyrophoric liquids.
- Self-heating substances, like the alkoxides of most alkali metals, produce heat in reaction with air but without being ignited by an external source. They differ from self-reactive and pyrophoric substances because they only ignite in large quantities over a longer period of time.
- Substances which in contact with water emit flammable gases, like alkali metals and calcium carbide, do just what it sounds like they do.
- Oxidizing liquids, like hydrogen peroxide and nitric acid, produce oxygen, making the surrounding air more likely to ignite.
- Oxidizing solids, like sodium nitrate and potassium permanganate, create oxygen as well.
- Organic peroxides, like methyl ethyl ketone peroxide, have the potential to explode, burn easily, or ignite under friction. They may be solid, liquid or paste.
- Substances corrosive to metal, like sulfuric acid and acetic acid, can degrade metal. This breakdown may release harmful gases into the air.
Hazcom Health Hazards
Substances labeled “health hazards” have been found to cause acute or chronic effects simply through exposure.
- Acute toxicity. Materials classified as “toxic” have been found to harm humans. Substances will also be categorized based on their most likely exposure route: oral, dermal (contact with skin), as gas, vapor or dust.
- Skin corrosion and irritation. Corrosive substances have been found to produce irreversible skin damage within at least four hours of contact. Irritating materials produce “reversible” damage; it can be effectively treated.
- Serious eye damage and irritation. “Serious damage” describes materials that have been found to cause tissue damage in the eye, or a serious impairment in vision. “Irritation” refers to substances that “change” the eye in any way after application.
- Respiratory or skin sensitization. Substances that increase the sensitivity of airways may lead to asthma. Skin “sensitizers” cause an allergic reaction upon contact.
- Germ cell mutagenicity involves materials that have been found to cause mutations in “germ cells,” the precursor cells to sperm and eggs. These mutations can be passed to children.
- Carcinogenicity. Substances like asbestos and cadmium can cause cancer.
- Reproductive toxicology. These substances have been found to cause “adverse effects on sexual function and fertility in adult males and females.”
- Target organ systemic toxicity. These substances affect a particular organ more than others. OSHA differentiates between materials that can have this effect after only one exposure and those that require long-term exposure.
- Aspiration toxicity. Substances that can be harmful upon entry through the mouth or nasal passages.
Hazcom Environmental Hazards
Obviously, “environmental hazards” pose a threat to the environment, generally aquatic ones.
You can find more information on how hazardous materials are classified in OSHA’s Guide to the Globally Harmonized System of Classification and Labeling of Chemicals (GHS).
For more information on construction accident explosions click here.