Academic journal article The Science Teacher

Safer Science

Academic journal article The Science Teacher

Safer Science

Article excerpt

Choose Biological Stains Carefully

Biological stains like basic fuchsin, Congo red, and methyl blue have been used in high school science labs for decades to enhance the visibility of microscopic structures like organelles in plant and animal cells and tissues. Though long considered risk-free, these stains may need to be reevaluated for safety and health issues, as some are suspected of containing carcinogens, toxins, and mutagens.

Carcinogenicity unknown?

With potential health and safety issues like these, it is the "not knowing" that is troubling. Teachers considering the use of biological stains in their labs can weigh the risks by consulting various resources before making an informed decision.

Start by reviewing the "ABC of Safety in the Biological Sciences" (, which lists stains commonly used in labs and their risks, such as "highly toxic" and "potential carcinogen."

Another step is to check out the chemical nature of the stain being considered. Good resources include the Safety Data Sheets (SDS), formerly called Material Safety Data Sheets (MSDS), which manufacturers must provide for hazardous chemical products under OSHA's newly revised Hazard Communication Standard (HCS). Important information on biological stains related to these concerns can be found in the following sections of the new SDS:

* Section 2 identifies all hazards associated with the chemical.

* Section 8 lists permissable exposure limits for a chemical as well as personal protective equipment needed to use it.

* Section 11 covers routes of exposure to a chemical, symptoms of exposure, and possible acute and chronic effects of exposure.

As examples, here are some safety concerns stated in the SDS or MSDS documents for several stains:

* Basic fuchsin: Mutagenic for mammalian somatic cells (

* Congo Red: Slightly hazardous in case of skin contact (http://bit. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.