2013年2月12日 · T-BuLi is a 3-3-4. I can't find NFPA data on straight diazomethane (which may be because nobody in their right mind ever works with the stuff in its pure gaseous form; it's always used in a dilute diethyl ether solution, and even then is never sold or shipped that way) but it would probably be a finalist, as the gas is acutely toxic ...

The following are some values given from different sources for the "health" rating (scale of 0-4, where 0 is the most benign and 4 the most hazardous) for elemental mercury: The National Institute for Occupational Safety and Health (NIOSH): Health = 1 MSDS from NIST: Health = 2 MSDS from Fischer Scientific: Health = 3

2017年2月27日 · "Section 4.2.3.3 of NFPA 704 provides three different methods to rate multiple chemicals. In addition, professional judgment must still be used to increase or decrease the rating to more accurately assess the degree of hazard, perhaps due to quantities, or synergistic effects of the chemicals, etc.

2023年4月5日 · The ComplianceSins.com says following about this NFPA 704 Diamond with 3-4-2-COR_OXY Hazard Level Indicators: Please NOTE: The symbol in the white Special Hazard area of this specific diamond is not considered an "authorized symbol" by the NFPA.

2017年4月28日 · Why Ethanol has the blue health hazard rating of 2 in NFPA 704 where as both Acetone and Methanol which are far more toxic than Ethanol have a rating of only 1? (Click on each link to see the NFPA

2019年6月15日 · DPD (N,N-diethyl-p-phenylenediamine) is used in free chlorine colorimetric analysis since it reacts with Hypochlorous acid and Hypochlorite ions acquiring a pinkish color that can be quantitatively related to the concentraction of …

2016年11月28日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

2019年4月7日 · From the fully non-lethal stuff, the first that comes to mind is sulfur hexafluoride, $\ce{SF6}$ ($6.17~\mathrm{kg/m^3}$). It is the stuff that people use to artificially make their voice lower (similar to helium making it higher) and it has a 0000 NFPA rating.

2016年1月27日 · $\begingroup$ There is this incident that involves t-BuLi. Yes I know it's not a Grignard but if you read the article, which goes in a lot of technical detail, you might agree that it could have very well happened with a Grignard reagent and the main issue was not the high flammability of t-BuLi but low safety standards in the lab.

2017年1月9日 · Is there any substance that's a 4-4-4 on the NFPA diamond? 6. Isopropyl alcohol forming peroxides. 8.