Wednesday, November 19, 2008

one mL does NOT exactly equal 1 cc (i millilitre does NOT equal 1 cubic centimeter)

one mL does NOT exactly equal 1 cc (i millilitre does NOT equal 1 cubic centimeter)

We sometimes find someone who thinks so much like us, that they say, they are a man or woman after my own heart.

Happily, I found one.

I was having a discussion with a nurse who said that one cc (cubic centimeter) was exactly the same thing as one mL (milliliter). I told her that 1) mL is the preferred term of art, and that 2) they are not exactly the same.

She did not agree. So, as Dr. John usually does, I used other sources to prove up my case !
Point 1...mL preferred to use rather than cc in medicine
http://64.233.169.132/search?q=cache:ABQkwl-VHq4J:www.ms-information.org/medical/formulary There is shown a table indicating 12.6 percent of prescribing errors are the result of using "cc" when "mL" is proper.

http://en.wikipedia.org/wiki/Cubic_centimeter
There is currently a movement within the medical field to discontinue the use of "cc" in prescriptions and on medical documents as it can be mis-read as "00" if poor handwriting is used, which can result in a massive, even lethal, overdose of medication. In the United States, confusion resulting from using "cc" to mean "mL" accounts for 12.6% of all errors associated with medical abbreviations.[1] While "cc" is not officially prohibited per the Joint Commission's "Do Not Use" list of prohibited abbreviations,[2] it is on the list as a candidate for possible inclusion on future lists, with "ml" or "milliliters" as suggested replacements.

The mass of one cubic centimetre of water at 3.98 °C (the temperature at which it attains its maximal density) is equal to 1 gram.














Point 2, cc is not the exact same thing as mL (cubic centimeter is not the same exactly as millilitre)

Source 1
http://64.233.169.132/
Under the "Prohibited Abbreviation" section

http://www.funtrivia.com/askft/Question46602.html
sequoianoir

Unfortunately, 1ml does not equal 1cc. There is a difference when you go to 5 decimal places.

The metric system has it roots in Paris in 1793. In addition to decimal system proposals, units of length, mass and volume were provisionally created. (A brass standard of the provisional metre was made: it is preserved in the Conservatoire des Arts et M├ętiers, Paris.) This was when the LITRE was first defined as a measure for liquids, this being an appropriately sized volume for commercial use. As the 19th century drew to a close, very precise measurements were needed in the fields of Physics, Chemistry and engineering. In 1889 the "Standard Kilogramme" was created. This was supposed to be the same as 1 litre of distilled water at its maximum density -ie. at a temperature of 4 degrees celsius. The LITRE then became officially defined as 1 kilogramme of pure water at 4°C. Unfortunately there was a very small error and it was not until 1907 that it was detected. The "1889 Standard kilogramme" was discovered to have a mass of 1000.028 cc of pure water at 4°C and so it followed that a LITRE was 1000.028 cc. A decision was taken to leave the kilogramme as the "Standard" but to divide the LITRE into 1000 equal parts and to call this division by a new name the millilitre (ml).
From 1907 millilitres were used as the standard unit of liquid and volume measurement.
So 1 millilitre then equalled 1.000028 cc and 1 cc equalled 0.999972 ml.
Accordingly 1 millilitre of pure water at 4°C had a mass of 1 gramme

Apr 21 04, 4:32 PM
sequoianoir

In 1964 the General Conference of Weights and Measurements re-defined the LITRE as a true measurement of volume and so equal to 1000 centimetres cubed (cm3 or cc). This changed the specification of the litre, by the fact that its new definition is directly related to the metre as a measurement of volume and no longer to the kilogramme.
However, the millilitre remained as per the original specification and the ml calibration of scientific vessels used in very accurate analytical work is not 1/1000th of a litre where a litre = 1000cc, but where 1ml of pure water at 4°C has a mass of 1 gramme.
So 1ml does not equal 1cc

Apr 21 04, 4:33 PM

Source 2
http://www.blurtit.com/q980432.html
"For practical purposes, they are equivalent, but not exact. 1000 ml is exactly 1 liter. 1000cc's is not exactly 1 liter. "

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