Actually, He has about 13/14th the lifting power of H2. 4/~28 vs. 2/~28
the density of air.
https://en.wikipedia.org/wiki/Lifting_gas
Dave Lane
Principal
Clavis Technology Development
On 4/5/19 11:25 AM, Alan Hall wrote: ---
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> Remember theGraf Hindenburg Zeppelin disaster?
>
> That's why today's blimps use helium instead. It had 4 x less lifting
> power than hydrogen, but it's basically inert.
>
> Alan
> Ol' USAFR Flight Surgeon and sometimes pilot
>
>
>
> On Fri, Apr 5, 2019 at 10:47 AM Richard Palluzi <
> 000006c59248530b-dmarc-request**At_Symbol_Here**lists.princeton.edu> wrote:
>
>> I find it difficult to believe that anyone benefits from this type of
>> incredibly risky demonstration. I call to everyone‰??s attention that NFPA 45
>> Fire Protection for Laboratories Using Chemicals in Chapter 12 requires
>>
>>
>>
>> 12.2* Instructor Responsibilities. Where instructors are performing
>>
>> demonstrations or students are conducting experiments
>>
>> using hazardous materials*, the instructor shall be required*
>>
>> *to perform a documented hazard risk assessment,*
>>
>> *provide a safety briefing to students, provide adequate personal*
>>
>> *protective equipment (PPE), and place a safety barrier*
>>
>> *(as required) between students and the demonstration or experiment*
>>
>> *to prevent personal injury.*
>>
>> 12.2.1* Instructors in teaching labs shall be trained and
>>
>> knowledgeable in fire safety procedures, emergency plans, the hazards
>> present in the lab, the appropriate use of PPE, and
>>
>> how to properly conduct a hazard risk assessment.
>>
>>
>>
>> I think few, if any, of these types of experiments would survive a real
>> hazard assessment.
>>
>>
>>
>> I also mention that there is an entire section 12.3.2 on Performance of
>> Experiments or Demonstrations.
>>
>>
>>
>> 12.3.2.1 Experiments or demonstrations for students involving
>>
>> open flames; fire; or the use of flammable, reactive, toxic
>>
>> or corrosive chemicals shall be performed in accordance with
>>
>> 12.3.2.1.1, and 12.3.2.1.2, 12.3.2.1.3, or 12.3.2.1.4.
>>
>>
>>
>> 12.3.2.1.1 Experiments or demonstrations shall be performed
>>
>> in a location that does not block access to the primary
>>
>> means of egress from the laboratory work area.
>>
>> 12.3.2.1.2* Experiments or demonstrations that involve or
>>
>> produce hazardous quantities of fumes, vapors, particulates,
>>
>> or gases shall be performed in a chemical fume hood or other
>>
>> ventilation device adequate to capture the materials being
>>
>> evolved. This includes demonstration hoods or other devices
>>
>> that meet the requirements of ANSI/AIHA Z9.5 2.1.1.
>>
>>
>>
>> 12.3.2.1.3 Experiments or demonstrations involving chemicals
>>
>> that are performed outside a fume hood where the separation
>>
>> distance in 12.3.2.1.4 is not possible shall be performed behind
>>
>> an impact-resistant plastic or tempered-glass safety shield.
>>
>> (1) The shield shall be at least 0.610 m (24 in.) high and shall
>>
>> wrap 180 degrees around the hazard or extend at least
>>
>> 0.305 m (12 in.) beyond the hazard in both directions.
>>
>> (2) The shield shall be secured to the work surface with bolts
>>
>> or clamps to keep it in place.
>>
>>
>>
>> 12.3.2.1.4 Experiments or demonstrations involving chemicals
>>
>> that are performed outside a fume hood where a shield is not
>>
>> utilized shall be performed in a location that is at least 3.05 m
>>
>> (10 ft.) from students.
>>
>>
>>
>> 12.3.2.2 Experiments or demonstrations using flammable
>>
>> liquids and open flames shall be performed by a knowledgeable
>>
>> instructor.
>>
>>
>>
>> 12.3.2.3 In educational and instructional laboratories where
>>
>> experiments are conducted by students, the instructor shall be
>>
>> responsible for conducting a safety briefing prior to the start
>>
>> of each experiment to review the hazards of the chemicals
>>
>> used, the personal protective equipment required for
>>
>>
>>
>>
>>
>> This section was specifically added by the committee due to the number of
>> accidents, near misses, and incredibly lucky incidents that keep occurring
>> in schools during well meaning but incredibly poorly planned and
>> implemented demonstrations.
>>
>>
>>
>> I encourage all members to seriously read these requirements and carefully
>> reconsider any type of demonstration that has significant risk. We can
>> teach a chemistry without having to make students stand in front of an
>> explosive mixture.
>>
>>
>>
>> Richard Palluzi
>>
>> PE, CSP
>>
>>
>>
>> *Pilot plant and laboratory consulting, safety, design,reviews, and
>> training*
>>
>> www.linkedin.com/in/richardppalluzillc/
>>
>>
>>
>> Richard P Palluzi LLC
>>
>> 72 Summit Drive
>>
>> Basking Ridge, NJ 07920
>>
>> rpalluzi**At_Symbol_Here**verizon.net
>>
>> 908-285-3782
>>
>>
>>
>> *From:* ACS Division of Chemical Health and Safety
>> *On Behalf Of *DAVID Katz
>> *Sent:* Friday, April 5, 2019 4:55 AM
>> *To:* DCHAS-L**At_Symbol_Here**PRINCETON.EDU
>> *Subject:* Re: [DCHAS-L] Safety with Hydrogen-Filled Balloons
>>
>>
>>
>> As a demonstrator, I have used hydrogen and hydrogen-oxygen filled
>> balloons. They are always filled right before use and kept away from any
>> ignition source or possible source of static electricity. I would also use
>> lecture bottles of hydrogen so I could fill the balloons in class. The
>> cost of the lecture bottles, as opposed to standard cylinders, was minimal
>> in view of the safety of not having to move the filled balloons from the
>> lab to the classroom. For anyone using hydrogen-filled balloons for
>> demonstrations, one or two balloons, of reasonable size, are sufficient.
>> Although, I perfer a large test tube filled with as close to 100% hydrogen
>> hydrogen as possible. I can reduce the lighting in the classroom and we
>> can watch the hydrogen burn slowly and then observe the condensation formed
>> on the walls of the test tube.
>>
>>
>>
>> When I did my research, I used lecture bottles of reactive or flammable
>> gases attached to the reaction apparatus when needed. Proper stands and
>> clamping were used for the lecture bottles. Again, the cost of the lecture
>> bottles was minimal for the increased safety.
>>
>>
>>
>> David
>>
>> _________________________________________________________________________
>>
>> David A. Katz
>> Chemist, Educator, Expert Demonstrator, Science Communicator, and
>> Consultant
>> Programs and workshops for teachers, schools, museums, and the public
>> 5003 Canby Dr. * Wilmington, DE 19808-1102 * USA
>> voice/fax: (302) 509-3282 * email: dakatz45**At_Symbol_Here**msn.com
>> Visit my web site: http://www.chymist.com
>> _________________________________________________________________________
>>
>> ----- Original Message -----
>>
>> *From:* Wilhelm, Monique
>>
>> *To:* DCHAS-L**At_Symbol_Here**PRINCETON.EDU
>>
>> *Sent:* Thursday, April 4, 2019 2:49 PM
>>
>> *Subject:* Re: [DCHAS-L] Safety with Hydrogen-Filled Balloons
>>
>>
>>
>> *I was always taught to only use balloons for inert gases and that is what
>> we follow where I am. *
>>
>>
>>
>> Monique Wilhelm
>>
>> Laboratory Manager
>>
>> Department of Chemistry & Biochemistry
>>
>> University of Michigan ‰?? Flint
>>
>>
>>
>> *From:* ACS Division of Chemical Health and Safety [
>> mailto:DCHAS-L**At_Symbol_Here**PRINCETON.EDU
>> Merlic
>> *Sent:* Thursday, April 04, 2019 1:39 PM
>> *To:* DCHAS-L**At_Symbol_Here**PRINCETON.EDU
>> *Subject:* [DCHAS-L] Safety with Hydrogen-Filled Balloons
>>
>>
>>
>> Colleagues,
>>
>>
>>
>> Following up on the explosion at IIT-Bombay which injured a professor and
>> 2 interns:
>>
>>
>> https://www.hindustantimes.com/mumbai-news/explosion-at-iit-bombay-injures-professor-2-interns/story-i8UkvjMhnKnDeLyjKUj8iM.html
>> <https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.hindustantimes.com%2Fmumbai-news%2Fexplosion-at-iit-bombay-injures-professor-2-interns%2Fstory-i8UkvjMhnKnDeLyjKUj8iM.html&data=02%7C01%7C%7Cd87c0f25f79444368c1608d6b92e804a%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636900006697916981&sdata=cyrQ9FxtiYFKvWV%2B5XDUFDToi1a90CnK6vMMx7sn3W4%3D&reserved=0>
>>
>>
>>
>> And the dramatic acetylene balloon explosion:
>>
>> http://www.esdjournal.com/static/Kansas/dauer%20truck.htm
>> <https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.esdjournal.com%2Fstatic%2FKansas%2Fdauer%2520truck.htm&data=02%7C01%7C%7Cd87c0f25f79444368c1608d6b92e804a%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636900006697926986&sdata=CZcNv2eBV%2Bfs8j0XEpbOl9qJzooft7zHnaX2i579V9k%3D&reserved=0>
>>
>>
>>
>> This raises questions about the very common synthetic technique used in
>> research labs of using hydrogen-filled party balloons for small scale
>> reduction reactions at atmospheric pressure. Researchers often fill party
>> balloons with 1-5 liters of hydrogen at a regular gas cylinder, sometimes
>> walk through the lab to their hood, and then connect the balloon to a
>> reaction flask. (All that in contrast with hydrogenation under pressure in
>> a Parr reactor using fixed high pressure lines.)
>>
>>
>>
>> 1. Have there been reports of explosions when using hydrogen-filled
>> balloons for lab reduction reactions?
>> 2. What safety precautions should be followed when balloons are used?
>>
>>
>>
>> I can envision a number of things to do to avoid or discharge static
>> electricity, but wonder if others have experience in this.
>>
>>
>>
>> Thanks,
>>
>> Craig Merlic
>>
>>
>>
>> Professor of Chemistry
>>
>> UCLA Department of Chemistry and Biochemistry
>>
>> Executive Director
>>
>> UC Center for Laboratory Safety
>>
>> http://cls.ucla.edu
>> <https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fcls.ucla.edu&data=02%7C01%7C%7Cd87c0f25f79444368c1608d6b92e804a%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636900006697936997&sdata=e%2FdZo9Rt0xsowneoL9IzU7eoFKyw9h8sB97MDGe0Fec%3D&reserved=0>
>>
>> Los Angeles, CA 90095-1569
>>
>> Voice: 310-825-5466
>>
>>
>>
>>
>>
>> --- For more information about the DCHAS-L e-mail list, contact the
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>>
>> --- For more information about the DCHAS-L e-mail list, contact the
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>>
>> --- For more information about the DCHAS-L e-mail list, contact the
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>> **At_Symbol_Here**acsdchas
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>
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