The TSA rule for carry-ons is somewhat confusing. http://www.tsa.gov/traveler-information/3-1-1-liquids-rule
Their rule is titled 3-1-1 for carry-ons is misleading n that one would think it means 3 ounces even though it is cleared up on their website as 3.4 ounces (100 mL). It would be much simpler and end any confusion once and for all if they used 100-1-1 as a reminder. The middle “1” is suppose to refer to a one quart bag and that can be easily confusing to someone who doesn’t know what a quart is or if someone confused it with a British quart. At least if they implied a 1 L bag there can be no confusion. The fact that people are confused has led to an explanation via this website: http://blog.tsa.gov/2009/02/3-oz-or-34-oz-what-gives.html 3 oz or 3.4 oz? What gives??? Short answer: 3.4 oz. For more details, read on… OK, here’s the scoop. If the U.S. would have switched to the metrics system in the 70s, this wouldn’t be an issue. How many of you out there had to learn the metric system in school only to never use it… The rest of the article is quite interesting even though the TSA will now use in its communications “3.4” instead of 100 mL. Here it states 3.4 without any mention of it being a nice rounded 100 mL: http://www.aerosolproducts.org/traveling-tips-aerosol-products/ From: Michael Payne Sent: Thursday, 2014-07-03 15:17 To: U.S. Metric Association Subject: [USMA:54090] RE: Metric Size Limits on Airport Security Sign - BBC I’ve talked to TSA people in the US, the official literature and signs may say 3 oz, but the agents know it as 3.3 fl oz or 100 ml. Ive been told a couple of times that my toothpaste (100 mL) is too large, whereupon I show them the 100 mL and they say OK it’s fine! Note that toothpaste in the USA is sold my weight not volume. Not much help with international travel. Mike Payne On 03 Jul 2014, at 16:53, Martin Vlietstra <[email protected]> wrote: There is a legal problem with fluid ounces in international travel. Do you mean UK fluid ounces or US fluid ounces? Once you are on an internal US flight, it is quite clear that they mean US fluid ounces.. From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: 03 July 2014 16:07 To: U.S. Metric Association Subject: [USMA:54087] Metric Size Limits on Airport Security Sign - BBC My cell phone captured a couple of photographs (attached) this morning of a BBC television report about increased airport security. I notice that the sign displays size limits in milliliters only. I think the sign is intended for people entering the United States. Perhaps the sign makers concluded that ounces would only confuse most of their target audience. David Pearl www.MetricPioneer.com 503-428-4917
