Hazardous Materials

The history of NH3’s IDLH Limits

The history of ammonia’s Immediately Dangerous to Life or Health (IDLH) levels is a classic example of how occupational safety standards evolve as toxicological data becomes more refined. Since the concept was first introduced in the 1970s, the ammonia limit has undergone significant downward revisions based on a better understanding of acute human tolerance.

Styrene Tank explosion and fire on chemical tanker Stolt Groenland (Report & Video)

On 28 September 2019, a cargo tank containing styrene monomer on board the Cayman Islands-registered chemical tanker Stolt Groenland ruptured due to runaway polymerization. The catastrophic rupture released a large quantity of vapor into the atmosphere, which subsequently ignited. Fire-fighting efforts by the emergency services took over six hours and involved more than 700 personnel

What are the LEL correction factors for the top 5 direct reading instruments?

So I asked Google Gemini… What are the LEL correction factors for the top 5 direct reading instruments? I asked this as I wanted a side-by-side comparison of the DIFFERENT correction factors for these five (5) different meters. Some of the variation is 100% greater, so the moral of the story is that when you

Double Fatality – Welding on ATM Flammable Storage Tank (GRAPHIC)

There are very few instances where OSHA uses such clear language, but in 1910.252(a) they use the phrase “absolutely certain” and for good reason! This explosion occurred at a wastewater treatment plant in the city of Gumi, South Korea, on October 19, 2016. 1910.252(a)(3)(i) Used containers.No welding, cutting, or other hot work shall be performed

Is trans-loading a HHC/EHS exceeding its TQ a PSM or RMP “covered process”?

I have had a numerous discussions with companies regarding this new push for “trans-loading”. Trans-loading is defined as: “Transloading means the transfer of a hazardous material by any person from one bulk packaging to another bulk packaging, from a bulk packaging to a non-bulk packaging, or from a non-bulk packaging to a bulk packaging for

Know your LEL Detector’s Limitations (Humidity)

Low humidity makes most LEL (Lower Explosive Limit) detectors read lower than they should, because catalytic‑bead sensors depend on moisture for heat transfer and baseline stability. This can lead to under‑reporting of gas concentration, slower response, and—in extreme dryness—temporary sensor desensitization. Below is a clear, technically grounded explanation based on how LEL sensors work and

Process Safety Alarms and the “Wolf Syndrome”

“Wolf Syndrome” in the context of false alarms refers to a pattern where repeated false alerts cause people to stop responding, even when a real danger appears. It’s based on the classic “crying wolf” concept and is widely discussed in psychology, emergency management, and safety‑system design. The term is not a medical diagnosis—it’s a metaphorical

NIOSH 2026 Request for Information (RFI) on NH3 IDLH values

In March 2026, NIOSH issued a formal request for information to update the IDLH Value Profiles. While ammonia has an established IDLH of 300 ppm, the agency is seeking new toxicology and human health effects data to refine these values. The Focus: The RFI specifically looks for “weight-of-evidence” data on how chemical modes of action—such

Ammonia and Olfactory Fatigue revisited in a 2026 Study

I stumbled across this international study regarding community effects from a large scale NH3 release in 2022. The study wanted to validate or in-validate community complaints years after the event. Residents, numbers unknown, had been complaining of “loss of smell” after being exposed to hundreds of ppm’s of NH3. The study was interesting in that

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