0.3 mL versus 0.5 mL versus 1 mL barrels: resolution matters — setting out what I have, and where I think it stops being reliable.
A follow-up question about 0.3 ml versus 0.5 ml that I did not know to ask the first time.
The earlier thread answered what I asked. What I should have asked is below, and I think it is the one that matters.
The arithmetic in the opening post is right; the assumption feeding it is the part to check.
Graduation spacing is worth checking before you buy rather than after. Some 1 mL barrels are marked every two units and some every one, and that changes what doses you can read.
Correct me on the arithmetic if it is wrong; I would rather know.
Where I part company with the opening post, and it is a narrow parting.
0.3 ml versus 0.5 ml was covered in the wiki last year and the page has a review date on it, which is a better starting point than my memory of a thread.
That is clearer than the version I had in my head. Thank you.
U-100 means the barrel is graduated for a solution containing one hundred units of insulin per millilitre. For anything that is not insulin, the units are simply hundredths of a millilitre.
The version of 0.3 ml versus 0.5 ml that I was taught turned out to be a teaching simplification. Useful, and not true in the way I had assumed it was.
I had written a reply contradicting post #3 and deleted it. Here is what survived.
Whatever the answer on 0.3 ml versus 0.5 ml turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, invite the correction.
Confirming post #7 from a second method, which matters more than confirming it from a second person.
Sharps containers are a legal requirement for disposal in several jurisdictions and a sensible precaution everywhere. A rigid sealed container is the minimum.
The claim is narrower than it sounds, and deliberately so.
The reason 0.3 ml versus 0.5 ml is hard to answer is that the obvious measurement and the relevant quantity are not the same thing, and substituting one for the other is silent.
Post #8 answers the question as asked. The question underneath it is different.
U-100 means the barrel is graduated for a solution containing one hundred units of insulin per millilitre. For anything that is not insulin, the units are simply hundredths of a millilitre.
Not a conclusion. A place to stand while looking for one.
I read post #10 twice before replying, because I had assumed the opposite.
Reading the barrel at eye level matters more than any equipment choice. Parallax at a shallow angle is enough to shift a reading by a graduation.
If anyone has run this properly I would rather read that than my own guess.
Since 0.3 ml versus 0.5 ml keeps coming up, it should probably be a maintained page rather than a recurring thread. I am happy to draft it if someone with more direct experience will review it.
Narrowing post #12, because the general version has more than one answer.
Syringe barrel size: common sizes are 0.3 mL, 0.5 mL, and 1.0 mL. Smaller barrels are more legible for small doses. Larger barrels hold larger volumes. Choose based on your dose.
The general case is well covered; this is the awkward specific one.
What I can speak to on 0.3 ml versus 0.5 ml is narrow, so I will keep it narrow rather than generalising from it. Beyond that boundary I do not know.
Adding a note of thanks rather than an opinion. I did not know most of that.
Sharps containers are a legal requirement for disposal in several jurisdictions and a sensible precaution everywhere. A rigid sealed container is the minimum.
I would call that likely rather than established.
0.3 ml versus 0.5 ml is a question about a distribution, not about a value, and treating it as a value is what produces the confident wrong answers.
On 0.3 ml versus 0.5 ml, I would rather understate and be corrected upward than overstate and be quoted. That is a house style here and it is a good one.
U-100 means the barrel is graduated for a solution containing one hundred units of insulin per millilitre. For anything that is not insulin, the units are simply hundredths of a millilitre.
Post #19 and I disagree about the size of the effect, not about the direction.
A detachable luer needle plus hub can retain enough volume to matter. Whether it matters to you depends on your dose, and the arithmetic is worth doing once.
That is the honest state of it as of this week.
Taking post #23 at face value and following it one step further.
Sharps containers are a legal requirement for disposal in several jurisdictions and a sensible precaution everywhere. A rigid sealed container is the minimum.
The reasoning is more useful than the number, which is why I have shown it.
One caution on 0.3 ml versus 0.5 ml: everything above assumes the underlying documentation is what it claims to be. That assumption is doing real work and is rarely stated.
Sensible. I would want the same detail before I acted on it either.
Post #23 put the caveat in the right place and I want to underline it.
U-100 means the barrel is graduated for a solution containing one hundred units of insulin per millilitre. For anything that is not insulin, the units are simply hundredths of a millilitre.
I would put the burden of proof on the interesting explanation, not the dull one.
I had written a reply contradicting post #27 and deleted it. Here is what survived.
Practical experience of 0.3 ml versus 0.5 ml, offered as one case with the conditions stated, not as a general finding. Conditions first, because they are what make it interpretable.