increases the risk of exposure substantially. Planning should include consultations with colleagues who have experience in handling the substance safely and in protocols of use. Experts in the institution’s EHS program are a valuable source of information on the hazardous properties of chemicals and safe practice. They also need to be consulted for guidance regarding those chemicals that are regulated by federal, state, and local agencies or by institutional policy. Thoroughly review the wealth of information available in the MSDS, the literature, and toxicological and safety references.

When planning, always consider substituting less toxic substances for highly toxic ones. Also, be sure to use the smallest amount of material that is practicable for the conduct of the experiment. Other important factors to be considered in determining the need for additional safeguards are the likelihood of exposure inherent in the proposed experimental process, the toxicological and physical properties of the chemical substances being used, the concentrations and amounts involved, the duration of exposure, and known toxicological effects. Plan for careful management of the substances throughout their life cycle—from acquisition and storage through destruction or safe disposal. Document these plans, and review them with personnel doing the work, as well as others in the laboratory. Finally, include a method for receiving feedback that can be incorporated into policy revisions, allowing for continuous improvement of the procedures.

6.D.2 Experiment Protocols Involving Highly Toxic Chemicals

Before the experiment begins, prepare an experiment plan that describes the additional safeguards that will be used for all phases of the experiment from acquisition of the chemical to its final safe disposal. The amounts of materials used and the names of the people involved should be included in the written summary and recorded in the laboratory notebook.

The planning process may demonstrate that monitoring is necessary to ensure the safety of the experimenters. Such a determination is made when there is reason to believe that exposure levels for the substances planned to be used could exceed OSHA-established regulatory action levels, similar guidelines established by other authoritative organizations, or when the exposure level is uncertain.

People who conduct the work should know the signs and symptoms of acute and chronic exposure, including delayed effects. Arrange ready access to an occupational health physician, and consult with the physician to determine if health screening or medical surveillance is appropriate.

6.D.3 Designated Areas

Experimental procedures involving highly toxic chemicals, including their transfer from storage containers to reaction vessels, should be confined to a designated work area in the laboratory. This area, which may be a laboratory chemical hood or glove-box, a portion of a laboratory, or the entire laboratory module, should be recognized by everyone in the laboratory or institution as a place where special training, precautions, laboratory skill, and safety discipline are required.

Post signs conspicuously to indicate the designated areas. It may also be prudent to post any relevant LCSS outside the laboratory door. The designated area may be used for other purposes, as long as all laboratory personnel comply with training, safety, and security requirements, and they are familiar with the emergency response protocols of the institution.

In consultation with the institution’s EHS experts, the laboratory supervisor should determine which procedures and highly toxic chemicals need to be confined to designated areas. The general guidelines (section 6.C) for handling hazardous chemicals in laboratories may be sufficient for procedures involving very low concentrations and small amounts of highly toxic chemicals, depending on the experiment, the reagents, and their toxicological and physical properties.

6.D.4 Access Control

Restrict access to laboratories where highly toxic chemicals are in use to personnel who are authorized for this laboratory work and trained in the special precautions that apply. Administrative procedures or even physical barriers may be required to prevent unauthorized personnel from entering these laboratories.

Keep laboratory doors closed and locked to limit access to unattended areas where highly toxic materials are stored or routinely handled. However, security measures must not prevent emergency exits from the laboratory. Be sure to make special arrangements for emergency response, including after normal work hours. Use locks to secure refrigerators, freezers, and other storage areas. Keep track of authorized personnel, and be sure to retrieve keys and change locks and access when these people no longer work in the area.

Keep a detailed inventory of highly toxic chemicals. The date, amount, location, and responsible individual should be recorded for all acquisitions, syntheses, access, use, transport, distribution to others, and disposal. Perform a physical inventory every year to verify active inventory records. A procedure should be in place to report security breaches, inventory discrepancies, losses, diversions, or suspected thefts.

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