Course:SPPH381B/TermProject/Tylenol -Alex Kitt/Support Infrastructure/Chemical Hazards

Controls for Euthanizing Agents

Elimination and Substitution

The underlying cause for the use of many of these euthanizing chemicals is that they need to be used on the laboratory animals. To eliminate these chemicals, either laboratory animals would need to be entirely eliminated, or fewer animals could be used. This follows the "3 R's" principle: Replace, Reduce, and Refine. Given current technologies and FDA requirements, it is not possible to completely replace animal testing. Reducing the number of animals may be a viable option, with one advancement being that the LD50 test (in which doses of medicine are increased until 50% of animals die) is banned in some places, including the UK.

Replacing the type of euthanizing agent is also a possibility to reducing hazards. For example, while carbon dioxide may cause hypoxemia, it is less hazardous than halothane (which causes narcosis) or nitrous oxide (which is addictive and causes long-term health effects) . However, the use of euthanizing agents less hazardous to animals may be undermined by animal ethics considerations, as these replacements may cause more stress.

One other approach would be to not euthanize animals following testing (unless further tests are required post mortem).

Engineering Controls

* General and Local ventilation: to prevent airflow of toxic chemicals to workers, downdraft tables and fume hoods may be used

* Enclosing equipment/work processes: involves special containment tanks where animals are euthanized. For example, one automated system developed is able to euthanize up to 70 cages of mice without having to move them using carbon dioxide. This eliminates the need for animals handling, and protects workers from euthanizing agents

* Non-gaseous euthanizing agents: Instead of using gaseous euthanizing agents, injected liquids or pills could be used. However, this may increase animal handling and painful procedures, thereby increasing animal distress. Furthermore, workers are at greater risk for needle-stick injuries.

Administrative Controls

Education is key in preventing researchers from being exposed to euthanizing agents. Ensuring employees understand the rationale was well as the procedures to handling chemicals is key. Furthermore, ensuring employees understand how to properly handle animals may reduce exposure of workers to the euthanizing chemicals.

Personal Protective Equipment

The suggested PPE is very standard laboratory equipment, along with respiratory protection. The respiratory protection requires the use of proper respirator and fit testing, as well as medical testing of the employees prior to use. There must also be a respiratory protection training course, which involves proper use, cleaning, and maintenance of the respirators, as well as training on the hazards that the workers will be exposed to.