You Have Safety Questions? We Have Safety Answers!

««« By the STAO Safety Committee
The STAO Safety Committee welcomes enquiries, with respect to safety issues, from STAO members. Please send your questions to the Safety Committee Chair (refer to page 4 ‘Committee Chairs’). Your questions and the STAO Safety Committee responses may be published in Crucible, particularly if the information is deemed of general interest to other STAO members. Anonymity, however, will be guaranteed.

QUESTION # 28: Is it safe for students to perform investigations using urine in the school science laboratory?

RESPONSE: Investigations using urine only become hazardous if students come into contact with urine other than their own. Accordingly, students should only handle their own urine, including its disposal, to ensure that infections cannot be transmitted from one person to another. Students should wash their own glassware and teachers should wear gloves when subsequently handling it. Disinfection of contaminated equipment using a freshly-made 1% aqueous solution of sodium hypochlorite or autoclaving is recommended. These precautions, in addition to normal safe hygienic practices (washing hands, etc.), will ensure that any risks become negligible. Further guidance on the safe study of human body fluids is available in the STAO publication Stay Safe!

However, if teachers wish to introduce students to the role of urinalysis in diagnosing and monitoring certain disorders, another alternative worth consideration is to purchase simulated urine. This is available from most laboratory suppliers. Simulated urine kits allow students to test for pH as
well as abnormal constituents such as albumin, glucose, ketones and microbes.

QUESTION # 29: Are there specific chemicals or processes that are specifically hazardous for pregnant women which should completely be avoided?

RESPONSE: The effects of chemical exposure on fertility and pregnancy of female teachers and students of childbearing age are important consid¬erations because of the practical nature of science classes in biology and chemistry. There should be WHMIS data sheets for all chemicals that are found in a school. Any chemical that is identified as mutagenic or teratogenic would put the developing baby and the mother at risk, and the risk is determined by the exposure time and concentration. However, it is unlikely that most such chemicals would be found in a school. Notable exceptions

include (i) suspected mutagens (acetamide, acrylonitrile, colchicine, and Congo Red,) and (ii) suspected teratogens (diethyl phthalate, and gallic acid) which are still offered by many school science suppliers.

If you are concerned about a particular chemical, you can contact your Board of Health and Safety Officer who may have access to additional references about chemical exposure of female staff. The Safety Committee is going to undertake a research task to see how this is dealt with in other occupations, and will communicate those results through the Crucible when available.

The new Safer Use of Chemicals in School Science Laboratories resource and the STAO Hazardous Chemicals CD (both available from the STAO Science Store at www.stao.ca) may be helpful