Biosafety Science


Biosafety Science
Estimate Hazard
Estimate Exposure
Risk Assessment and Characterization
Risk Management
Protocols and Procedures
EPA Risk Assessment Review Process


In general, biosafety begins with making the workplace safe whether it be a laboratory, fermentation plant, farm, zoo, ranch, fish farm, fishing boat, etc. Further, the general population must be kept safe. Finally, the environment must be protected.

Chemical and physical hazards of non-living processes and events are finite. We know how much chlorine gas was contained in an overturned tank car and can respond accordingly. The hazard of ultraviolet light exposure on the skin and its relationship to natural levels of melanin production is reduced in know ways (the SP numbers) by chemical filters in sunscreens, even though many persons choose to ignore the hazard. Chemical and physical hazards indeed can be subtle and complex. Consider the chain of events and circumstances that had to come together to produce the Challenger destruction.

Biohazards are even more difficult to assess and predict by virtue of the defining attribute of life, reproduction. Thus, prediction of biohazard is confounded by the possibility of uncontrolled increasing amounts of hazardous material. The famous case of "Typhoid Mary" illustrates this point. She worked as a food handler without realizing that she was a carrier of typhoid. She did not have symptoms of the disease. Yet she was a walking biohazard factory, continually shedding the typhoid bacteria, and contaminating the food she prepared. In turn, the bacteria grew and infected the people consuming the food.

Biosafety and risk assessment are closely connected. One definition of risk assessment is:

"risk assessments are science-based estimates of the human health risk faced by a population exposed to a particular substance. The risk should be stated as a range of probabilities."

We shall consider risk assessment later. However, the above definition focuses on human health. We should consider hazards and risks broadly. The television news broadcasts were filled with adverse effect pictures of wild life covered with crude oil from the Exxon Valdez spill in Prince William Sound, Alaska. Biosafety is a cross-cutting policy issue that also encompasses considerable trade, export, import, and shipping/transhipment of products that are not genetically-engineered. These include "non-commodity" crops ("orphan commodities", indigenous natural products, and "lost crops") and exotic crops and new (non-genetically engineered) hybrid introductions. The traffic includes not merely non-modified "food crops", but feed crops, trees, flowers, microbial organisms such as mushrooms, yeasts, and other fungi, bacteria, algae, insects, molluscs(snails), birds, bioremediation technologies, aquatic macroorganisms (e.g., ornamental fish), and livestock.

Biosafety is a new issue in shipping and transhipment. Hitherto, much of risk analysis in, e.g., Africa, has been confined to addressing a series of specific commodity crop biosafety issues (e.g., genetically-modified soybean) facing the commercialization of industrialized country GMOs. Although the question of field testing and risk management at country field levels has been extensively treated, the issues of risks in shipping and transhipment have had little discussion and analysis.

Types of hazards

The potential for hazard of biological materials can be divided into the four categories of infectious, allergic, toxic, and environmental hazards. Of these, infectious and environmental hazards are the results of the continuing growth of the organism to produce the undesirable effect. Allergic and toxic effects may or may not involve concurrent growth of the organism.

  1. Infection hazard - the potential for disease in man, animals, and plants following exposure to the living organism or virus;
  2. The toxic, allergenic or other biological effect of the non-viable organism or cell, its components or its naturally occuring metabolic products;
  3. The toxic, allergenic or other biological effect of the product expressed by the organism;
  4. Environmental effects.

Infectious - An infectious organism is on that can colonize (grow on or in) another organism and thereby cause a pathology (disease). We are all familiar with skin infections of various sorts in humans such as the "burning, itching sensation between the toes" that occupies so much television commercial time in the U.S. Such topical fungal infections are very common and due to providing a welcome humid habitat for the fungus.

In fact, many kinds of organisms can infect many others. Bacteria can cause stem rot of mushrooms. Fungi and bacteria can infect insects and are used as biocontrol agents to avoid chemical pesticides. Bacteria can infect other bacteria. Viruses apparently infect most, if not all life forms.

Allergic - Allergic reactions are pathologies resulting from contact with a specific chemical entity. When the entity is a product of an organism, the chemical is a biohazard. One of the most common classes of allergens is plant pollen. In humans, the common allergic response is some form of inflammation. This can range from mild discomfort through incapacitation to death through anaphylaxis. For example, persons highly sensitive to bee stings must be extremely cautious and often carry bee sting kits in case of an encounter.

Toxic - Toxic effects are those which, like allegens, are produced by a pathologic reaction to a specific chemical material made by another organism. The toxin can be either contained in the other organism (endotoxin) or released from the organism (exotoxin).

Endotoxins are released by the disintegration of the cell and are often complex molecules containing lipids, carbohydrates, and protein as components. They are relatively heat stable, often resisting ordinary cooking. They are usually less toxic than exotoxins. However, there the unfortunate occurance wherein bacteria contaminated the pipeline feeding the bottling of saline for hospital use prior to the sterilization step. The bacteria were killed in the sterilization process but the endotoxin released from the killed bacterial cells was lethal upon injection.

Exotoxins are proteins. They lose their toxicity upon heating. However, they can be extremely potent. For example, the most powerful poisons known on a weight basis are the botulism toxins. In commercial food production, heat and/or acid is used to detoxify the botulism toxin. Most modern botulism poisonings are due to inadequate heating in home canning. However, it was not all that long ago that the Bon Vivant company closed because of deaths resulting from ingesting inadequately heated canned vichysoisse.

Last Modified: May 21, 2001
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