NH3 Safety

A guest editorial by Norm Olson, President of the NH3 Fuel Association.

The relative safety of NH3 (ammonia) is one of the most debated topics surrounding the adoption of NH3 fuel. Inaccurate and misleading information has been widely circulated on the topic. A thorough examination of the facts will show that the use of NH3 in energy applications will not only meet the most stringent safety standards currently in place worldwide, but that NH3 will be safer to use than many leading transportation fuels.

Two highly credible risk assessments analyze the safety of NH3 vs gasoline and other fuels, and both of them conclude that NH3 would be as safe as, or safer than, gasoline, methanol, LPG (propane), CNG (compressed natural gas), or hydrogen.

Unfortunately, there are a number of people who believe that NH3 poses unacceptable risks when used as a transportation fuel, even though there are no credible, quantitative risk assessments supporting this position.

This article is the first in a series that aims to provide accurate and useful information surrounding the relative safety of NH3 fuel.

NH3 Basics

NH3 has a decades-long history of acceptably safe use as a fertilizer. It is the second most transported chemical in the world and is both a common, natural substance and a man-made chemical. Naturally occurring production of NH3 is approximately equal to man-made production on an annual basis.

NH3 is not a known carcinogen, it is not a greenhouse gas, and it has an ozone depletion potential of zero.

The only emissions produced when combusting NH3, assuming the use of a standard catalytic after-treatment system, are atmospheric nitrogen and water.

Objective, credible data on NH3 provides the only logical means of evaluating its relative safety in transportation fuel applications but, unfortunately, there is a significant amount of misinformation and confusion.

Not all chemicals are equally toxic

A primary source of confusion in the US originates from the regulatory reaction to a release of the unrelated chemical methyl isocyanate from the Union Carbide plant in Bhopal, India in 1984. The release killed thousands (some reports estimate more than 8,000 deaths) and injured over 500,000. In response to this disaster, the US created the Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA). One result of this Act was the establishment of a list of approximately 300 chemicals that were arbitrarily labeled “extremely hazardous,” irrespective of the fact that some of the chemicals on the list would be more accurately classified as “slightly toxic” by the accepted numerical safety-rating systems.

Methyl isocyanate is unquestionably an extremely toxic chemical. In fact, it is 400 times more toxic than NH3, based on LC50/4-hour ratings. Classifying diverse chemicals, with this magnitude of difference in toxicity levels, into one class and labeling them all as “extremely” hazardous is not a precise system and it has led to many inaccurate conclusions.

Category 1 or Category 4: which is safer?

A second source of confusion regarding the relative safety of NH3 is the way in which the US Occupational Safety and Health Administration (OSHA) refers to toxic chemicals. OSHA developed a list of what it labels “acutely toxic” chemicals, and it differentiates the degree of toxicity with a 1-4 category rating.

Click to enlarge. Source: OSHA/GCCA.

But it is not immediately obvious, without going to OSHA’s website, whether Category 1 or Category 4 is the most toxic. Upon checking, you will find that Category 1 is the most toxic and Category 4 is the least toxic. Nor is it immediately obvious whether a Category 4 chemical, the least toxic in the “acutely toxic” list, is safe or not.

This confusion is made worse if you compare OSHA’s toxicity ratings with the ratings used by another important agency in the US, the National Fire Protection Association (NFPA). Both agencies classify chemicals using four levels of toxicity, however, the NFPA assigns Level 4 as the most toxic and Level 1 as the least toxic – the exact opposite of the OSHA rating system!

Regulators and investors should base decisions on credible data

Objective data and two technical risk assessments prove that NH3 is safe enough to use in transportation fuel applications and can meet the most restrictive safety codes currently in place worldwide. Misconceptions about NH3 can be corrected by providing factual information in a clear and concise fashion.

The ultimate safety performance of NH3 fuel will result from engineering design decisions; there are no technology developments or breakthroughs needed to insure acceptably safe use of NH3 fuel.

The clear superiority of NH3 fuel in emissions, efficiency, and economics, along with the fact that it can be produced sustainably using only renewable power, air, and water, make NH3 fuel the optimal choice as the world’s primary liquid fuel.

Future articles here will address these safety issues in greater depth, and interested parties can refer to the risk assessments, both of which are freely available at the NH3 Fuel Association’s website.

A guest editorial by Norm Olson, President of the NH3 Fuel Association.



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