perienced users and consultants. Chemistry is becoming the universal language of science, and the planners of new chemistry buildings should anticipate that space requirements in some situations may differ considerably from those associated with traditional chemistry laboratories. For example, mutual scientific interests among combinatorial chemists, synthetic chemists, and molecular biologists have encouraged the placement of modern biology laboratories in close proximity to organic and inorganic synthesis laboratories to facilitate collaboration.

Future chemistry laboratory buildings may likely have requirements for laboratory space appropriate for experiments involving human pathogens. If a requirement such as this arises, the project team will need to become familiar with consensus standards for the design and operation of safe biological laboratories. An authoritative reference on biological safety is Richmond and McKinney (1993). Guidance for facility safeguards is provided according to four levels of risk that are based on the potential for occupationally acquired infection and the severity of disease.

Areas that can present unique hazards—such as high-pressure facilities; radiochemistry, x-ray diffraction, nuclear magnetic resonance (NMR), and high-energy laser laboratories; and laboratories for research in which the risk of explosion is high—are likely to be included in the program of requirements for new facilities or major renovation projects. Other potentially hazardous areas include those that contain large volumes of chemicals, such as chemical storage or hazardous waste accumulation areas. Each of these areas will present special hazards for which expert consultation will be required to ensure that appropriate criteria are identified to achieve a safe design.

The concept of controlled access is relevant in all areas that may be hazardous to health. The objective is to protect persons who are not assigned to the laboratory from exposure that may compromise health. The degree of control over access should correspond to the level of risk. For example, in high-risk areas, access should be limited to individuals specifically trained and assigned to work in the area. In low-risk areas, it may be sufficient to design laboratory corridors so that they are not perceived as public thorough fares.

The configuration of space so as to control access merits careful consideration, particularly for laboratory areas that require limited access. It is important that both the controlled areas and the access points to these areas be easily recognized as such. There should be a way to inform the visitor of appropriate entry procedures or prohibitions against entry. The location of a controlled access area should be convenient for the laboratory staff. It is equally important that access control measures be no more restrictive than the potential risks require; otherwise, they will be quickly abandoned by the assigned laboratory staff.