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Health & Safety Manual - Chemical Hygiene Plan

1.2 Health Hazards of Chemicals

1.2.1 Chemical Hazard Identification and Labelling
1.2.2 Safety Data Sheets
1.2.3 Labels

1.2.4 Other Chemical Information and Safety Data Sheet Resources
1.2.5 Chemical Exposure Routes
1.2.6 Toxicology/Health Effects of Chemical Exposure


OSHA broadly defines hazardous chemical as any chemical that is classified as a health hazard or simple asphyxiant in accordance with the Hazard Communication Standard (29 CFR 1910.1200). Health hazard means a chemical that is classified as posing one of the following hazardous effects: acute toxicity (any route of exposure); skin corrosion or irritation; serious eye damage or eye irritation; respiratory or skin sensitization; germ cell mutagenicity; carcinogenicity; reproductive toxicity; specific target organ toxicity (single or repeated exposure); aspiration hazard. The criteria for determining whether a chemical is classified as a health hazard are detailed in Appendix A of the Hazard Communication Standard (ยง1910.1200).

1.2.1 Chemical Hazard Identification and Labelling
The CHP ensures that information about chemical and physical hazards is communicated to laboratory personnel and students who may potentially come into contact with hazardous materials in laboratories. Effective hazard communication includes, but is not limited to: maintenance of current chemical inventories, providing ready access to Safety Data Sheets (SDS) for hazardous chemicals, proper labelling of chemical containers, posting of hazard signs where relevant, and training of laboratory personnel with regard to relevant hazards.

1.2.2 Safety Data Sheets
Chemical manufacturers are required to evaluate the hazards of chemicals they produce or import, and to provide this information to purchasers, at the time of shipment, through SDS's. Under OSHA's recently adopted Globally Harmonized System of Classification and Labelling of Chemicals (GHS), all hazardous chemicals manufactured in or imported to the United States of America will have accompanying SDS's in a standardized 13 section format. SDS's provide important information about a chemical's constituents, emergency aid/response measures, hazards, exposure control/protective equipment, among other information.

Laboratory staff are required to have immediate access to SDS's to aid them in evaluating the potential hazards of a substance prior to its use, as well as in the event of an emergency. SDS access and management is made available to all Columbia University research laboratories via ChemWatch. ChemWatch is a web-based database of more than 10 million SDS's, available in English and 30+ foreign languages, for immediate access by the Columbia University staff. Personnel or students who desire a copy of the SDS for any hazardous chemical with which they work or may be exposed can also contact their PI, supervisor, instructor or EH&S for a copy.

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1.2.3 Labels
Commercial suppliers of chemicals label chemical containers with the chemical name, hazard information, and safe storage conditions. These labels must never be defaced or obstructed unless an emptied and rinsed container is to be used for another purpose. Chemicals produced within laboratories must also be labeled in English to meet these requirements.

When chemicals are transferred from primary, labeled containers to portable, secondary containers/vessels, the New York City Fire Code requires labeling of the portable, secondary container with a chemical name(s). OSHA also requires labeling of portable, secondary containers under certain conditions, however it is good chemical hygiene practice to label all laboratory containers/vessels with a chemical name(s).

1.2.4 Other Chemical Information and Safety Data Sheet Resources

1.2.5 Chemical Exposure Routes
A hazardous chemical's SDS will identify likely routes of exposure (see Section 1.2.3 above). In general, hazardous chemicals can enter the body via inhalation, skin (or eye) absorption, ingestion, and injection.

  • Inhalation: For most chemicals in vapor, gas, mist, or particulate form, inhalation is the major route of entry. Once inhaled and deposited in lungs they can cause serious damage, from simple irritation to tissue destruction.
  • Skin (or eye) absorption: Dermal or skin contact can cause simple redness or mild dermatitis to severe damage like destruction of skin tissue.
  • Ingestion: Chemicals that inadvertently get into the mouth and are swallowed may harm the gastrointestinal tract or be absorbed and transported by the blood to internal organs where they can cause damage.
  • Injection: Substances may enter the body if the skin is penetrated or punctured by contaminated objects. Effects can then occur as the substance is circulated in the blood and deposited in the target organs.

Section 1.4 Minimizing and Controlling Chemical Exposure provides important information on reducing exposure to hazardous chemical in the laboratory.

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1.2.6 Toxicology/Health Effects of Chemical Exposure

While the subject of toxicology is quite complex, it is necessary to understand the basic concepts in order to make logical decisions concerning the protection of personnel from the effects of hazardous substances. Toxicity of a substance can be defined as the relative ability of that substance to cause adverse effects in living organisms. This ability is dependent upon several conditions. The quantity or the dose of a substance determines whether the effects of the chemical are toxic, nontoxic or even beneficial. In addition to dose, other factors influence the toxicity of a substance such as the route of entry, duration and frequency of exposure, and inherent variations between species and within species.

Understanding the basic concepts of chemical toxicity and the routes by which chemicals enter the human body can help in making critical decisions about the manner in which a hazardous substance should or should not be used. Decisions such as whether a hazardous substance can be substituted by a less hazardous one, or whether it should be used only with an engineering control, such as in a chemical fume hood, glove box and what PPE is necessary to protect the user from potential exposure.

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