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Cylinder Lifting Cart 2010-02-01
As luck would have it, we happened upon this lifting cylinder cart which appears to be similar to what our guys made in 1999 http://www.usasafety.com/caddy-gas-cylinder-lifting-dolly-1-cylinder-p-52.html
Eugene Ngai Chemically Speaking LLC
Gas Cylinder Lifting 2010-01-12
I could not attach the picture even when I downgraded the quality to the lowest setting. I would be happy to forward you it. I wish the Grapevine could create an area where we can drop these into
The Air Products Megasys group has wrestled with this problem for years. This is the group that at one point had over 1000 employees at customer sites to change gas cylinders and chemical containers. A variety of solutions have been tried with limited success. The best that I have seen is shown in the attached picture from 1999. The problem is the lift is a worm gear that is mechanically cranked, This can take some time to crank up and down to change a cylinder. I have seen others in which a piston is used, but it is so unstable that it is unsafe.
One of our maintenance guys improved on this for a fixed system by installing a electric motor and limit switches to bring it up and down.
As Jim has indicated, there is not an easy answer for this Eugene Ngai Chemically Speaking LLC
Sent: Tuesday, January 12, 2010 6:57 PM To: SEMI EHS Grapevine Subject: RE: Gas Cylinder Lifting SEMI Environmental Health & Safety Grapevine
Brandon, I think part of the problem is, there are so many different size cylinders and different gas cabinet designs. You may find one cart that fits one size cylinder or cabinet but not another…or when you have more than one cylinder in the cabinet it adds another layer of difference.
Usually most carts, assuming the gas cabinet is mounted on a flat floor, will do the job nicely. Use a single cylinder cart for a single cylinder. Remove the empty cylinder first. Properly store the empty cylinder, then using t he cart, install the new cylinder. Most Techs, usually don’t have much trouble doing this in a safe manner. If assistance is needed, your gas representative will normally be glad to demonstrate the technique.
Jim
Offgassing of Arsine and Stibine from Electric Fork trucks during Battery Charging 2010-01-15
Steve I don’t have that article, but it sounds like a good one to have. Can you provide me with the magazine/book it was in?
You hit upon an issue that many people are not aware of. For most facilities, lead battery charging operations are in well ventilated areas which people occupy on an infrequent basis. Since there have not been chronic or acute exposures reported from these areas, they are not monitored for arsine. Many people routinely get exposed to minor quantities of arsine on a periodic basis without ill effect, they just don’t know about it. The 2 most common sources are from lead batteries and acetylene. One of the demonstrations I did many years ago in the Specialty Gas ER course was to use a TLD 1 on a battery and acetylene to prove this(Acetylene also has Phosphine and Hydrogen Sufide). What many people forget with a toxic gas is what Paracelsus in the 1500’s stated “All Substances are Poisons. There is none which is not a Poison, The dose makes the poison”.
When I presented this fact to most safety professionals they had a dilemma. While they could accept the logic (technical thinking) they could not accept that fact that any amount of a highly toxic gas would not have a harmful affect (emotional thinking). You and the rest of the Grapevine now have this same dilemma. Can any amount of Arsine be OK?
Let me recap some facts on arsine exposures from my quick review of my files.
Most arsine poisoning cases reported in literature are due to continuous exposures in an industrial environment:
· Lead battery plant in charging area. · Workers using cyanide to extract gold. · Copper smelter and refining. · Ferrosilicon grinding and storage
In the early days of electric submarines, a number of sailors were poisoned by arsine when they recharged the batteries, but think about how many they had in that tight confined area.
Or where people have mixed the wrong things together
· Maintenance workers cleaning clogged drain using a standard drain cleaner (sodium hydroxide & aluminum chips). The drain was previously used for arsenic herbicides. · Farm workers and kids working in area of cattle dip tank charged with Chlorphenamidine and Superphosphate.
The two exposure cases in the home are reported to be:
Chronic arsine poisoning was also known as a rich persons disease in the 1800’s. Only rich people could afford wall paper. The green paints used were copper arsenate compounds. Most homes were very damp and microbes in the plaster walls digested the copper arsenate creating low levels of arsine. People that lived in these homes were continuously exposed.
There were some reports in 1989 that suspected that crib deaths may be related to arsine exposures. Some of the bedding used contained very low levels of arsenic and phosphorous used as fire retardant which was digested by fungus in the mattress. This report has since been refuted but pops up periodically.
I hope this helps. It’s probably more than you wanted to know but its important to know all the facts.
Eugene Ngai Chemically Speaking LLC
Sent: Friday, January 15, 2010 4:50 PM To: SEMI EHS Grapevine Subject: Offgassing of Arsine and Stibine from Electric Fork trucks during Battery Charging SEMI Environmental Health & Safety Grapevine We encountered a situation that I haven’t run into previously. We detected 5 to 10 ppb hydride gas (as arsine) from an ambient sample point in our clean room approximately 15 feet away from an electric fork truck charging station. On investigating with a portable detector, we detected up to 90 ppb approximately 3 feet from the truck.
There is a paper from Varma et al dated May 1988 “Stibine and arsine generation from a lead acid cell during charging modes under a utility load leveling duty cycle” that describes and quantifies this phenomenon. The paper measured results on a 2250Ah capacity battery. Our truck uses a 1425 Ah rated battery. The reaction seems to peak just as the battery reaches 80% charge or ~2.4 V per cell. Terminating the charge causes the gas concentrations to drop almost immediately.
Although our experience mirrors the process described in the paper, our concentrations seem high considering this fork truck is in a Class 10,000 clean room with ample air movement. The paper indicates that the rate of hydride generation (Most likely predominantly Stibine) will increase as antimony (and arsenic) leach from the cathodes of the battery, travel through the electrolyte and deposit on the electrodes. Our battery representative states that this antimony leaching condition would be exacerbated by a battery near end of life. This may be the case with our batteries.
Does anyone else have experience with this phenomenon? I am concerned that we seem to have stumbled on this accidentally because our charging station is in a Cleanroom monitored for arsine. What about other industrial applications using these trucks? It seems that this hazardous condition can be created without an adequate control. After all, most warehouses do not see air movement anywhere near that seen in clean rooms, and without our detectors, we would not have had warning of the developing hazardous condition.
I would appreciate any feedback that can be provided. Steven
Security vulnerabilities of fixed chemical sites 2004-04-28
Yes. Air Products has an extensive worldwide Security program which is modeled after this and the ACC guidelines. We have our own assessment tools which are on the CCPS website. Our program has been inexistence for over 2 years. We also lead the effort at the Compressed Gas Association which has a similar Guideline for gases Eugene Ngai
-----Original Message----- Sent: Tuesday, April 27, 2004 4:09 PM To: SEHS Grapevine Subject: Security vulnerabilities of fixed chemical sites SEMICONDUCTOR INDUSTRY ENVIRONMENTAL HEALTH & SAFETY (SEHS) GRAPEVINE
Does anyone on the Grapevine have experience with the following guidelines or their international equivalents?
"Guidelines for Analyzing and Managing the Security Vulnerabilities of Fixed Chemical Sites" by the Center for Chemical Process Safety of the American Institute of Chemical Engineers "Manual on Chemical Site Security Vulnerability Analysis Methodology and Model" by the Synthetic Organic Chemical Manufacturers Association.
If so, please contact Robert Barnes directly at RBarnesAZ@att.net. Thanks |
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