The purpose of LBNL’s Chemical Hygiene and Safety Plan is to establish procedures to protect employees from the hazards of the chemicals in their work area. This is also a legal requirement mandated by Federal Occupational Safety and Health Administration standards, including The Hazard Communication Standard, and the Exposure to Hazardous Materials in Laboratories Standard.
The OSHA Hazard Communication Standard (HCS) is intended to reduce the incidence of chemically related occupational illnesses and injuries. The Standard establishes the minimum requirements that employers must adhere to for communicating hazards to workers. This standard is often referred to as the “worker right-to-know” standard.
The scope of the HCS applies more directly to shop, trade, and craft personnel (i.e., Facilities).
For a more in-depth explanation of the HCS in plain English, please click here.
Laboratory workers are protected by a related but different OSHA regulation, “Occupational Exposures to Hazardous Chemicals in Laboratories.”
The “Lab Standard” relies on the technical judgment of line management to inform all people who work in their laboratories of the steps to protect themselves from hazardous exposures to chemicals in the laboratory and what to do if an exposure should occur.
Employers must develop and implement a “Chemical Hygiene Plan.” This plan is a description of the facilities, rules, procedures and policies of the Laboratory that are directed at minimizing employee exposures to hazardous chemicals during normal operations and during unplanned events such as chemical spills. Additional information on chemical hygiene and prudent laboratory practices may be found in 29 CFR 1910.1450 Appendix A.
Toxicology is the study of the nature and action of poisons.
Toxicity is the ability of a chemical substance or compound to produce injury once it reaches a susceptible site in, or on, the body.
A material’s hazard potential is the probability that injury will occur after consideration of the conditions under which the substance is used.
The potential toxicity (harmful action) inherent in a substance is exhibited only when that substance comes in contact with a living biological system. The potential toxic effect increases as the exposure increases. All chemicals will exhibit a toxic effect given a large enough dose. The toxic potency of a chemical is thus ultimately defined by the dose (the amount) of the chemical that will produce a specific response in a specific biological system.
There are four main routes by which hazardous chemicals enter the body:
Most exposure standards, such as the Threshold Limit Values (TLVs) and Permissible Exposure Limits (PELs), are based on the inhalation route of exposure. These limits are normally expressed in terms of either parts per million (ppm) or milligrams per cubic meter (mg/m3) concentration in air. If a significant route of exposure for a substance is through skin contact, the PEL and/or TLV on the SDS will have a “skin” notation. Examples of substances where skin-absorption may be a significant factor include: pesticides, carbon disulfide, carbon tetrachloride, dioxane, methanol, acetonitrile, mercury, thallium compounds, xylene, and hydrogen cyanide.
Examples: carbon monoxide or cyanide poisoning.
Examples: strong acids or alkalis.
Examples: arsenic affects the blood, nervous system, liver, kidneys and skin; benzene affects bone marrow.
Example: heavy metals.
Example: exposure to alcohol and chlorinated solvents; or smoking and asbestos.
A gas is a substance that conforms to the shape of a container in which it is held and acquires a uniform density inside the container. It exists in the gaseous state at room temperature and pressure.
A vapor is the gaseous phase of a material that is ordinarily a solid or a liquid at room temperature and pressure.
Solubility is the property of a solid, liquid or a gaseous substance to dissolve in a solvent. When considering the toxicity of gases and vapors, the solubility of the substance is a key factor. Highly soluble materials, like ammonia, irritate the upper respiratory tract. On the other hand, relatively insoluble materials, like nitrogen dioxide, penetrate deep into the lung. Fat-soluble materials, like pesticides, tend to be retained longer in the body and have a cumulative effect.
An aerosol is composed of solid or liquid particles of microscopic size dispersed in a gaseous medium.
The toxic potential of an aerosol is only partially described by its airborne concentration. For a proper assessment of the toxic hazard, the size of the aerosol’s particles must be determined. A particle's size will determine whether a particle is deposited within the respiratory system and the location of deposition. Particles above 10 micrometers tend to be deposited in the nose and other areas of the upper respiratory tract. Below 10 micrometers, particles enter and are deposited in the lung. Very small particles (<0.2 micrometers) are generally not deposited but exhaled.
Chemicals and hazardous materials can be classified according to the effect they have on individuals.
Irritants are materials that cause inflammation of mucous membranes with which they come in contact. Inflammation of tissue results from exposure to concentrations far below those needed to cause corrosion.
Irritants can also cause changes in the mechanics of respiration and lung function.
Long-term exposure to irritants can result in increased mucous secretions and chronic bronchitis.
A primary irritant exerts no systemic toxic action, either because the products formed on the tissue of the respiratory tract are nontoxic or because the irritant action is far in excess of any systemic toxic action.
Example: hydrogen chloride.
A secondary irritant’s effect on mucous membranes is overshadowed by a systemic effect resulting from absorption.
Simple asphyxiants are gases that displace oxygen.
Chemical asphyxiants reduce the body’s ability to absorb, transport, or utilize inhaled oxygen. They are often active at very low concentrations (a few ppm).
· Carbon monoxide
· Hydrogen sulfide
Primary anesthetics have a depressant effect upon the central nervous system, particularly the brain.
Hepatotoxic agents cause damage to the liver.
Nephrotoxic agents damage the kidneys.
Neurotoxic agents damage the nervous system.
The nervous system is especially sensitive to organometallic compounds and certain sulfide compounds.
Some toxic agents act on the blood or hematopoietic system. The blood cells can be affected directly or the bone marrow (which produces the blood cells) can be damaged.
There are toxic agents that produce damage of the pulmonary tissue (lungs) but not by immediate irritant action. Fibrotic changes can be caused by free silica and asbestos. Other dusts can cause a restrictive disease called pneumoconiosis.
A carcinogen is an agent that can initiate or increase the proliferation of malignant neoplastic cells or the development of malignant or potentially malignant tumors.
Known human carcinogens include:
A mutagen interferes with the proper replication of genetic material (chromosome strands) in exposed cells. If germ cells are involved, the effect may be inherited and become part of the genetic pool passed onto succeeding generations.
A teratogen (embryotoxic or fetotoxic agent) is an agent that interferes with normal embryonic development without causing a lethal effect to the fetus or damage to the mother. Effects are not inherited.
A sensitizer is a chemical that can cause an allergic reaction in normal tissue after repeated exposure to the chemical. The reaction may be as mild as a rash (allergic dermatitis) or as serious as anaphylactic shock.
Carcinogens are agents that cause neoplasms (tumors) in humans and/or animals. Below are links to the OSHA Carcinogen Web Site and several lists of carcinogens from various sources. These include lists from the National Toxicology Program (NTP) and the International Agency for Research on Cancer (IARC):
Reproductive toxins are chemicals that can damage the reproductive systems of both men and women. Exposure to these agents before conception can produce a wide range of adverse effects including reduced fertility, unsuccessful, an abnormal fetus, reduced libido, or menstrual dysfunction. Maternal exposure after conception may cause perinatal death, low birth weight, birth defects, developmental and/or behavioral disabilities, and cancer.
This is a respiratory protection guide from 3M Corporation that contains a table of odor thresholds. These start on page 15 of the enclosed PDF document. An odor threshold is the lowest airborne concentration that can be detected by a population of individuals. While odor thresholds can serve as useful warning properties, they must be used cautiously because olfactory perception varies among individuals. Moreover, as the table indicates, some odor threshold concentrations are above their respective Occupational Exposure Limits. For assistance in interpreting these data, contact your Division's EHS Health and Safety Representative.