Hazardous Materials
I will again reference my 30 years of teaching emergency response courses and the surprising lack of hazard awareness so many "certified technicians" lack. The one that get a lot of attention is the relationship between TOXIC and PHYSICAL hazards when the HAZMAT is both toxic and flammable. I have shared many tips over the years, but the following is one that every safety professional should get tattoed onto their forearm: 1% = 10,000 ppm So, let's look at that relationship and think that we measure Lower Explosive Limits (LEL) in percentage and most often use ppm to measure inhalation hazards from vapors and gases. We can begin to see the relationship. This is a key relationship to understand when working in known hazardous atmospheres. We tend to focus on the acute risks when dealing with flammable liquids and gases: ignition of the vapor/gas and the consequences of that event. And YES, we need to be well aware of that hazard. But remember this: Most of the flammables we work around have LELs less than 5%; most are in the 2-3% range. Those percentages translate into the tens of thousands of parts per million (ppm). Take gasoline for example: Membership Content
Since gas use was integral to the UH accident and since compressed gas cylinders present serious safety issues, several specific examples of improper gas and gas cylinder usage are detailed here. 1. Cylinders in the laboratories adjacent to POST 30 as well as in several laboratories located in different buildings, contained Teflon tape on the CGA connection threads to the cylinder valve
There are two (2) types of Asphyxiants:
These different types of asphyxiants behave differently and cause harm differently.
Chlorine is EXTREMELY HAZARDOUS, with an IDLH of 10 ppm and a TLV of 0.5 ppm (just above the odor threshold for most). Chlorine is heavier than air (VD > 2.5), and when released, it forms a greenish-yellow gas with a pungent, irritating odor that follows the terrain at ground level. The mean odor threshold for chlorine lies between 0.2 and 0.4 ppm. Chlorine is a NON-FLAMMABLE gas; however, it is a powerful oxidizing agent, reacting explosively or forming explosive compounds or mixtures with many common chemicals. Chlorine immediately reacts with both organic and inorganic materials it comes into contact with to form chlorides. The primary route of exposure is INHALATION. Chlorine is very volatile, with a Boiling Point of -29°F. So, although it is shipped as a liquidfied gas under pressure, once the primary containment is breached, it will quickly become a GAS. The Vapor Pressure of Cl2 is 6,450 mm hg @ STP. Remember, BP and VP have inverse relationships. As BP goes down, VP goes up, and vice versa. An excellent standard to follow is that water at STP has a VP of 25 mm hg and a BP of 212°F. Cl2 is the opposite: High VP (6,450 mm hg) and Low BP (-29°F).
Recently, a facility experienced firsthand why the IFC and its state fire code PROHIBIT the movement of hazardous materials via the facility's "tunnel system." The code does not prohibit the use of the tunnel system or even in enclosed corridors. Still, the design requirements for these tunnel systems or enclosed corridors to move HAZMATs are usually not cost-effective. Yet, many facilities do not post signs or include in their HAZMAT/HAZCOM training that these specific areas are "off limits" for transporting HAZMATs. Here is what the IFC and State Fire Code require: (emphasis by me and the revised structure is by me)
The battle continues, this time outside process safety! I get these arguments routinely when people inquire if they can use their HHC/EHS as the media for pressure and leak testing. I can only assume that PHMSA is getting pushback by requiring water or other similar viscosity liquid to be used as the test medium. When hydrostatic pressure tests for cargo tanks are required in part 180, subpart H, the HMR requires that water or other similar viscosity liquid be used as the test medium (see § 180.407(g)(viii)). PHMSA understands that some stakeholders believe the requirement to use water—or other similar viscosity liquid—may be unduly restrictive. PHMSA has authorized the use of alternate test mediums for portable tank testing (e.g., DOT SP–20294, 20308, and 16163), but has not authorized this for cargo tanks. PHMSA requests comment on the following questions to evaluate authorizing additional liquids for hydrostatic testing cargo tanks: |
Partner Organizations I am proud to announce that The Chlorine Institute and SAFTENG have extended our"Partners in Safety" agreement for another year (2024) CI Members, send me an e-mail to request your FREE SAFTENG membership
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