Specimens in Carosafe®

What is Carosafe®?

Carosafe is a preservative and holding solution for biological specimens. It contains no formaldehyde and is not a tissue fixative. Most specimens in Carosafe® are first preserved with a formalin solution and then washed and placed in formaldehyde-free Carosafe®. This produces a formalin-preserved specimen that, when dissected, minimizes student and educator exposure to formaldehyde.

The primary component of Carosafe® is propylene glycol, a common ingredient used in cosmetics and foods. Propylene glycol is on the U.S. Food and Drug Administration’s (FDA’s) list of food additives that are generally recognized as safe. Holding specimens in Carosafe® reduces the presence of formaldehyde, thereby diminishing or eliminating unpleasant odor. However, Carosafe®-preserved specimens and their surrounding fluid do contain some residual formaldehyde, a by-product of the initial formalin preservation process. The amount present varies by specimen type.

What is the shelf life of a specimen?

Unopened specimens in Carosafe® fluid or Caropak® (our trade name for specimens damp-packed with Carosafe®) will keep for a very long time. A specimen taken out of its original package and returned to it will remain in good condition for at least several weeks, provided it remains damp with Carosafe®. For maximum shelf life, keep the specimen damp with Carosafe® when you are working with it and return it to its original package immediately after use. Washing a specimen with water may invite mold growth and deterioration, and exposing it to air for long periods may lead to drying, as can be expected with any preserved specimen.

How should I dissect and handle specimens?

The dissection should take place in a well-ventilated laboratory, and we recommend using the following good laboratory practices during the procedure:

• Each person handling preserved specimens must wear gloves, splash-resistant goggles, and a lab apron.
• Each person must thoroughly wash his or her hands after the procedure.

These practices must be followed whenever dealing with biological or chemical materials in the laboratory to ensure that the person handling the materials never directly contacts them.

Is Carosafe® harmful to pregnant women?

Carosafe®-preserved specimens do expose one to residual amounts of formaldehyde (a known carcinogen) as mentioned earlier. However, none of the components of Carosafe® itself would be expected to cause adverse reproductive effects, and it can be said that specimens preserved in Carosafe® are safe and should pose no undue health hazards to a pregnant woman or her unborn child in normal circumstances. For the utmost in safety, we recommend that women carefully consider avoiding unnecessary exposure to any chemical substances during pregnancy. For more information on this topic, click here.

How do I dispose of Carosafe® and specimens?

The components of Carosafe® are disclosed on its Material Safety Data Sheet (MSDS). In many localities Carosafe® can be disposed of in a sanitary sewer, i.e., poured down the drain, and specimens can be disposed of in a landfill, i.e., thrown in the trash. In others, this may not be the case. Always check with your local sewer and solid waste authorities before disposing of Carosafe® and Carosafe®-preserved specimens.

Download the MSDS (PDF)