Ammonium nitrate (AN) is a widely used chemical compound with several important applications. As a fertilizer, it helps feed billions. It is also the main component in many types of mining explosives, where it is mixed with fuel oil and detonated by an explosive charge. Increased global agriculture activities, combined with the rising demand for ammonium nitrate fuel oil (ANFO), mean that the market for ammonium nitrate is expected to grow at a compound annual growth rate (CAGR) of at least 4% over the next 5 years. However, the potentially explosive nature of ammonium nitrate (and the potential for its misuse) means that manufacturers, sellers, and users of this compound need to heed safety warnings or risk disaster.

How can we continue to reap the benefits of this versatile compound while minimizing the risks associated with its use? In this article, we will discuss the key learnings from the catastrophic 2020 ammonium nitrate explosion in Beirut and how further explosions can be prevented.

Ammonium nitrate – a market on the rise

The ammonium nitrate market is on an upward trajectory, with recent reports estimating a market size of $24 billion by 2026. This increase in market value has been catalyzed by the growing population, creating an increased demand for food supply and real estate. Incidentally, ammonium nitrate is a valuable resource for both industries.

Ammonium nitrate is a popular fertilizer since nitrogen is a key component of the two parts of the compound: NH₄ (ammonium) and NO₃ (nitrate). Not only can plants access nitrogen directly from the nitrate form of the compound, but the ammonium fraction can also be gradually converted to nitrate by soil microorganisms. These properties make ammonium nitrate a popular choice for vegetable growers, who prefer a readily available nitrate source for plant nutrition. Animal farmers use ammonium nitrate for pasture and hay fertilization, preferring it to urea-based fertilizers that can volatize from the soil before it is used by the plants. It is also highly soluble, making it well- suited for use in irrigation systems.

Ammonium nitrate's other predominant use is as a component in explosive mixtures used for mining, quarrying, and civil construction purposes. As part of ANFO, it accounts for 80% of the explosives used in North America. Unfortunately, as the components of ANFO are relatively easy to obtain, there is a potential for misuse in improvised explosive devices. This highlights the importance of proper control of this ammonium nitrate form to reduce its potential hazards.

Beirut disaster – the aftermath

On August 4, 2020, the capital of Lebanon, Beirut, was shaken by a catastrophic explosion that killed at least 218 people and left over 6,000 people injured. The main cause of the explosion was approximately 2,750 tons of ammonium nitrate stored in a warehouse at the Port of Beirut. This large amount of ammonium nitrate had been seized from an abandoned ship impounded in 2014. The stored fertilizer was ignited by sparks from a fire at an adjacent warehouse, creating an explosion that caused enormous property damage and left an estimated 300,000 people homeless. Two years on, the explosion continues to impact Beirut, with subsequent collapses of adjacent grain silos occurring in July and August 2022.

Aside from the human cost of the explosion, the economic impact is thought to be in excess of 6.7 billion US dollars. The explosion wiped out 90% of Lebanon’s grain reserves, adding to an already precarious food security situation in a country facing severe economic challenges. The environment must also have been affected by such a blast, although data is lacking. When the ammonium nitrate exploded, noxious gases including nitrogen oxides, ammonia, and carbon monoxide were released into the environment, causing chemical pollution and further harm to local people. Ecosystems are also damaged by this environmental pollution, with amphibians and aquatic life bearing the brunt of nitrate poisoning as the decomposition products transfer to the ocean.

Experts have analyzed the Beirut explosion and compared it to other similar ammonium nitrate disasters. In common with several other devastating explosions, the root cause of the explosion was deemed to be an uncontrolled fire. The stockpiling of such a large quantity of ammonium nitrate in one location amplified the impact of the explosion, and the urban nature of the storage location increased the number of blast injuries that resulted. Because of these analyses, recommendations have been made including initiating a Chemical Regulatory Agency to take control of chemical safety at a national level in Lebanon and improving planning for emergency responses to future events.

The explosive nature of ammonium nitrate

Most ammonium nitrate explosions take place during transport or storage (Figure 1), however to fully understand the risk factors for an explosion, it is important to appreciate ammonium nitrate’s chemistry and manufacturing processes.

Ammonium nitrate is made by the reaction of ammonia with nitric acid in water followed by careful evaporation of the water to yield a solid element:

NH₃ + HNO₃ → NH₄NO₃

Ammonia is usually derived from atmospheric nitrogen and nitric acid is prepared from the combustion of ammonia. These two starting products would not commonly be kept near one another. Manufacturing occurs in an aqueous solution because the reaction produces a significant amount of heat. The subsequent evaporation process has been the source of several explosions. Other sources of explosions relating to the manufacturing process include the inclusion of impurities, which can lower the stability of ammonium nitrate. Without adequate temperature control, it is also possible for ammonium nitrate to absorb water or change crystal forms leading to agglomerates that make it unsuitable for use.

Despite decades of study into the reactions of ammonium nitrate, the exact mechanisms of decomposition and explosion are not fully understood. This conundrum is in part due to the chemical complexity of the reaction but also the varying ambient conditions and potential contaminants. The following reaction has been hypothesized as the main detonation reaction:

2NH₄NO₃ → 2N₂ + O₂ + 4H₂O

One reason that ammonium nitrate is so explosive is that it contains in the same molecule both a fuel, in the form of the ammonium ion, and a strong oxygen- producing agent, nitrate. As decomposition occurs, heat is produced which initiates detonation and, because an oxygen source is already present, combustion accelerates rapidly. The result is the production of nitrous oxides, oxygen, water, and large amounts of heat and kinetic energy. These products cause an expansion in volume 1,000 times greater than the initial volume of ammonium nitrate, leading to catastrophic blast damage in the surrounding area.

Several processes, additives, and alternatives to ammonium nitrate have been tested in attempts to minimize the dangers of accidental explosions as well as general misuse (Table 1). Despite this, no perfect solution exists, and more work is needed to develop a safe and affordable alternative. Produced by CAS, an Insight Report exploring lessons learned from ammonium nitrate explosions emphasizes that “it is not enough to make fertilizers that do not accidentally explode; it is also important to make ones that cannot be easily made to explode.”

Table 1. List of alternative nitrogenous fertilizers

Alternative nitrogenous fertilizers have also been subject to consideration (Table 1). However, the alternative with the highest nitrogen content is a gas at room temperature, and toxicity prohibits its use. Mixing fertilizers that are high in nitrogen together with other macronutrients can produce effective fertilizer while reducing the risk of explosion.

Handling ammonium nitrate with care

Many stringent regulations and requirements for the safe handling and storage of ammonium nitrate already exist in several countries. In the US, the primary regulations were issued in 2001 by the Occupational Health and Safety Administration (OSHA), and additional guidance can be found in an advisory document issued in 2015 by OSHA in collaboration with the Environmental Protection Agency (EPA), and the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF). This advisory was issued as part of an ongoing government initiative to improve ammonium nitrate risk management and safety, as well as to help protect the environment.

The CAS Insight Report on ammonium nitrate safety highlights that its safe storage requires careful consideration of several variables (Figure 2). OSHA regulations stipulate that adequate ventilation is required in storage areas, which is key to preventing toxic gases and hot gases from accumulating as well as agglomeration. Other key safety factors accounted for in legislation include using non-combustible materials in storage areas, keeping temperatures below 130°F, limiting the amount of ammonium nitrate stored in one place, and ensuring adequate firefighting measures.

Legislation and guidelines are vital for the control of a dangerous substance like solid ammonium nitrate, but they can only improve safety if they are adhered to. Improving awareness of the dangers of ammonium nitrate and the importance of following existing guidelines would help prevent or at least greatly limit future catastrophic events.

Ammonium nitrate is a highly useful and economically important substance relied upon for agriculture and other industries throughout the world. However, the dangers of manufacturing and storing it have been highlighted by several devastating explosions over the last century. To improve this dangerous situation, it is paramount that the public is aware of the dangers of ammonium nitrate, and that safety measures are adhered to while suitable alternatives are sought.

If you would like to find out more, please download our Insight Report, “Ammonium Nitrate Explosions: Lessons Learned.”

Despite extensive effort and investment, in the seven months since the World Health Organization declared COVID-19 a pandemic, effective therapeutic treatments for patients suffering from this disease have remained elusive. To aid in the effort to identify effective antiviral treatments that can mitigate the virus’ impact, a group of scientists and technologists at CAS sought to identify possible drug candidates for treating COVID-19 with predictive machine learning models. Quantitative Structure-Activity Relationships (QSAR) methodology was used to build and test more than 40 models for priority viral protein targets 3CLpro or RdRp. The best performing classification models were applied to screen a set of over 150,000 chemical substances, including FDA-approved drugs. This work successfully identified a number of drugs now beginning to show clinical efficacy, including Lopinavir and Telmisartan, as well as many other candidate substances for consideration. 

We hope this effort, which combined human data curation and machine learning predictive models to successfully identify potential small-molecule drug candidates for COVID-19, highlights the value of synergy between humans and machines in drug discovery, while contributing to on-going antiviral research efforts for COVID-19 and beyond.

The last year has seen an unprecedented number of vaccine candidates directed at the COVID-19 pandemic. As of the end of February 2021, several vaccines had been conditionally approved, and others are close to such approval. It is likely that many more still in clinical trials will come to market in the next few years.

This report examines these vaccines and the related research effort, both traditional and forward-looking, to illustrate the advantages and disadvantages of their technologies, to denote the use of adjuvants and delivery systems in their application, and to provide a perspective on their future direction.

On this anniversary of one of the largest and most devastating industrial incidents ever recorded, we remember the tragedy of Beirut – a blast so immense that it was heard 200 km away in Cyprus. The epicenter of the detonation was at a port warehouse and the fuel was 2,750 tonnes of ammonium nitrate. 

Ammonium nitrate is one of the most widely used fertilizers, an important constituent of many other industrial compounds, such as mining explosives, and used as a nutrient for producing antibiotics and yeast. Like so many other chemicals used in industrial processes, it carries risk which can be mitigated through safe storage and robust handling procedures. 

The investigations in Beirut are still open, but it is thought that a fire started in a warehouse at the port and spread to an area where ammonium nitrate was stored; unsafe storage near fireworks and without isolation or fire prevention measures led to its explosion. Within seconds, this incident killed over 200 people, injured over 5,000 more, and left around 300,000 residents homeless. Sadly, this event was not unique, and explosions and fires caused by chemicals, such as ammonium nitrate, are all too common. Ultimately, if a substance can release energy rapidly, then it carries a potential explosion or fire risk. But why do certain chemicals possess these characteristics?

Weak chemical bonds and stable products make an explosive partnership

If a substance has weak chemical bonds, particularly if it yields stable products, it is likely to pose a risk of fire or explosion. Fuels, such as gasoline, burn because their combustion yields stable substances with stronger chemical bonds; in the case of gasoline, these products are carbon dioxide and water. Gasoline requires either heat or an ignition source, such as a spark or flame, to burn because the bonds in the fuel reactants are not easily broken.

For example, Figure 1 shows a conceptual model for a reaction such as the burning of gasoline. The purple line shows how the free energy changes during a reaction from reactants to products. When gasoline burns, it forms stable products (water and carbon dioxide) containing strong bonds, giving off a great deal of energy in the process. This is shown in the figure by the difference in height from the starting point on the left to the end of the reaction on the right. As the difference in free energy between the reactants and the products increases, the energy that can be released when the reaction occurs also increases.

In order to get from reactants to products, however, the molecules must have enough energy to start the reaction. Reactions often begin by breaking bonds, and strong bonds require substantial amounts of energy to break. Thus, for the reaction of a stable molecule to begin, a large amount of energy must be given to the reaction. This energy is called the activation barrier, and it is shown by the height of the hill in the middle of the reaction pathway.

Once the barrier has been surmounted, the reaction can occur. Since the free energy difference between reactants and products is large, the reaction of one molecule can provide sufficient energy to help other molecules to surmount the activation barrier. The reaction can then accelerate and be difficult to stop until the reactants are consumed. Once a fire starts with gasoline, it can be difficult to extinguish. In addition, because the products are gaseous (carbon dioxide and steam), the products occupy much more space than the reactants. The expansion of volume transfers energy to the surroundings; if the reaction occurs in an enclosed space, an explosion may occur. Since it requires more energy to cause gasoline to burn, it is easier to avoid actions which provide that energy and thus easier to prevent fires. 

Review examples of explosive chemicals here, and for additional chemical safety or substance resources, check out the Chemical Safety Library and CAS Common Chemistry. 

Other substances provide larger hazards. Many of these contain weak chemical bonds. Figure 1 (green line) also shows a model for a reaction such as combustion of a molecule containing a weak bond. Like gasoline, the difference in free energy (as shown by the difference in height) between the reactants on the left and the products on the right is large; the products contain strong bonds, and the reaction releases a large amount of energy when it occurs. The height of the barrier for this reaction, however, is much lower than that for the combustion of gasoline. 

Reactions often start with the breaking of a bond, and the presence of a weak bond provides an easy place for a reaction to begin. Once the bond is broken, the reaction can then move to completion. When the products are much lower in energy than the reactants, as in this case, the reaction of one molecule can release energy to cause other molecules to react; because the barrier to reaction is lower, more molecules can be induced to react from the reaction of one molecule of the substance in Figure 1 (green) than from the reaction of one molecule of the substance in Figure 1 (purple). The presence of the weak bond means that the reaction, once begun, can accelerate rapidly. If the products are gases, they will also transfer work to their surrounding; if the reaction is rapid enough, an explosion or detonation can occur. The lower barrier to reaction of a substance containing a weak bond means that it takes less energy to start its reaction, and so the ways in which it can be handled are more limited. In some cases, impact, friction, or sparks from handling can initiate reaction, and so handling of such substances requires much more care to prevent fire or explosion.

Azides (RN₃) illustrate this point perfectly. These substances contain three connected nitrogen atoms with bonds of unequal strength. Nitrogen atoms can form strong bonds – the triple bond between the nitrogen atoms in molecular nitrogen gas (N₂) is one of the strongest known chemical bonds; however, nitrogen atoms can also form single and double bonds, which are considerably weaker. One of the nitrogen-nitrogen bonds in azide is weak and doesn’t require much energy to break, driving rapid decomposition that yields N₂. Because the nitrogen-nitrogen bond in N₂ is so much more stable than the nitrogen-nitrogen bonds in the reactant azide, this decomposition releases large amounts of energy. 

Inorganic and organic azides have varying sensitivities. Inorganic sodium azide can be handled safely under everyday conditions but is deployed as a rapid gas generator in vehicle airbags, while highly volatile heavy metal azides, such as lead azide, are used as initiators for explosives. Organic azides are commonly used in the synthesis of more complex chemicals, including pharmaceuticals and polymers. Organic azides with either low molecular weight or high nitrogen (N) to carbon (C) atomic ratios can be explosive and there have been several reported incidents of laboratory explosions due to the formation of low molecular-weight azides from reactions between inorganic azides and dichloromethane. An azide-modified amino acid used for the preparation of modified proteins was also found to be explosive. 

Peroxides (ROOR) are another class of molecules with potentially explosive characteristics. Peroxides contain weak oxygen-oxygen bonds; when these bonds break, peroxides yield radical intermediates (free radicals) that are useful in chemical reactions. Radical intermediates are particularly useful for initiating polymerization, and they are commonly detected as intermediates in combustion; even small amounts of radicals can act as catalysts and, in some cases, they catalyze their own formation. Peroxides also fragment to yield molecular oxygen (O₂); while the oxygen-oxygen single bond is weak, the oxygen-oxygen double bond in O₂ is strong, so this fragmentation releases energy. 

The weak oxygen-oxygen bond means that peroxides can decompose easily, releasing free radicals and O₂, a volatile, explosive combination, particularly when concentrated. Several significant fires have been reported at chemical facilities that work with peroxides, including one in Texas, USA, when Hurricane Harvey and unprecedented flooding caused safety mechanisms to fail. Peroxides can also spontaneously form from the exposure of ethers to oxygen. These peroxides form crystals that can explode when subjected to physical shock, friction, or reaction with certain metals. Ethers are normally formulated with small amounts of inhibitors such as BHT (butylated hydroxytoluene, used as a preservative) to prevent the formation of peroxides. The inhibitors are consumed by oxygen; if ethers are kept for long periods of time in the presence of oxygen, the ethers will be susceptible to peroxide formation.

The fiery urge to become stable

Other substances have bonds that, while they do not break easily on their own, may react easily under certain conditions to form products that are much more stable. As new bonds are formed, energy is released as heat, fires, or explosions can result. For example, metal alkyls are used as catalysts in the synthesis of a wide range of chemicals and materials, but they are often pyrophoric, burning easily on contact with air. 

Trimethylaluminum, in particular, reacts with air or water to yield products with highly stable aluminum-oxygen bonds, resulting in fires and explosions.

Acrylates are used for industrial-scale polymerization; each acrylate monomer replaces its double bond with an additional single bond as it is incorporated into the polymer chain. This new bond is stronger than the cumulative strength of the double bond, so the polymerization reaction releases energy. The polymerization of acrylates and other alkenes is often performed using radical initiators such as peroxides to start the polymerization reactions, using the same reactivity that under other circumstances leads to their explosion. In large scale polymerization chambers, when the surface area to volume ratio is too low to dissipate the heat formed and when the inhibitors of uncontrolled polymerization are consumed, inactivated, or removed, acrylates can polymerize explosively. 

Similarly, solvents such as dimethyl sulfoxide (DMSO) can react with a variety of substances, such as acids, bases, and electrophiles, to reduce decomposition temperatures; reactions even at lower, seemingly safe temperatures may still lead to an explosion. 

Harnessing the great enabler of the modern world

At its center, chemistry is made possible by energy changes and for centuries, humans have harnessed and exploited this energy to travel the world, drive industry, and produce the very food on our tables, the clothes on our backs, and the fabric of our cities. We covet explosive and volatile chemicals for their energy and yet their power can have unexpected and devastating consequences. By understanding how to channel this energy in constructive ways and to better identify conditions when chemicals may react in unexpected and detrimental ways, we can anticipate explosive incidents before they happen and learn to prevent them.

For more information on ammonium nitrate, its hazards,and safety rules, download our full CAS Insights Report and watch our webinar that brings together key experts who will discuss the formulation options and the innovation landscape. 

Lipid nanoparticles (LNPs) have emerged as promising vehicles to deliver a variety of therapeutics in the pharmaceutical industry. Liposomal drugs, based on an earlier version of LNPs, have already been approved and applied to medical practice. LNPs have the ability to encapsulate and deliver therapeutics to specific locations in the body and release their contents at a specific time, which makes them desired platforms for further drug usage.

In this peer-reviewed article published in ACS Nano, the landscape of LNP-related publications in the CAS Content Collection is examined in detail. Also discussed are growth opportunities for LNP usage in the fields of antitumor therapeutics, nucleic therapeutics, and vaccine delivery systems, as well as the potential challenges of utilizing the material. Read the full publication here.

In recent years, AI application to chemistry has rapidly grown. While there has been numerous publicity about AI used in this manner, there hasn’t been a lot of in-depth analysis on its use and development in the chemistry field.

This peer-reviewed article published in the Journal of Chemical Information and Modeling studies the growth and distribution of AI-related chemistry publications within the CAS Content Collection. The volume of this research has dramatically increased since 2015. The article also examines interdisciplinary research trends, associations of AI in certain chemistry research topics, and an understanding of the future role of machine learning in the field. Read the full publication here.

The COVID-19 pandemic has motivated researchers across the globe to find effective drugs and therapeutics for treating the disease. Many efforts have focused on repurposing existing drugs used for other illnesses to save time. The CAS Biomedical Knowledge Graph was developed to identify drugs that can be repurposed to treat COVID-19.

This peer-reviewed article published in the Journal of Chemical Information and Modeling examines this graph and its results in greater detail. It shows how various molecules were analyzed according to molecular function and clinical trials. This graph not only provides an opportunity to accelerate innovation and research for COVID-19 but many other diseases as well. Read the full publication here.

Bioorthogonal chemistry is a set of methods that use the chemistry of non-native functional groups to analyze biology in living organisms. It allows organic synthesis that is traditionally performed in a laboratory to be performed in live cells. Instead of being used to prepare large amounts of materials like in a lab setting, this method is meant to covalently codify biomolecules.

This peer-reviewed article published in Bioconjugate Chemistry examines the most common reactions used in biorthogonal methods, their pros and cons, and how frequently they appear in other published literature. The study also analyzes other biorthogonal studies in the CAS Content Collection to determine how certain materials have been studied via bioorthogonal chemistry. Read the full publication here.

Going into the year 2022, one of the leading concerns worldwide is climate change. It is now widely accepted that one of the leading contributors to negative climate change is the burning of fossil fuels – the burning of fossil fuels such as coal or oil leads to the release of large amounts of carbon dioxide into the air, trapping heat in our atmosphere and causing global warming. 

Plastics, the material ubiquitously found in products ranging from grocery bags, car bumpers and even clothes, are traditionally made from synthetic polymers derived from petroleum. The building blocks of these polymers are either obtained directly from crude oil refining or synthesized from refining products. Currently, it is estimated that plastic manufacturing processes consume 8–10% of the global oil supply, with this number set to double by 2040. 

The production of petrochemicals and traditional plastics is still completely reliant on oil, and this non-renewable resource is rapidly being depleted from planet Earth. The problem with plastics is therefore multifold: traditional plastic production must eventually cease due to dwindling resources; this method of production damages our ecosystem, and many plastic products are not reusable, creating extraordinary amounts of waste, causing further damage through not being disposed of/recycled properly.

The average person can reduce their ‘ecological footprint’ and help the environment by reducing their use of single-use and disposable plastics, reducing packaging waste, and recycling responsibly. Manufacturers can equally improve their ‘ecological footprint’ by choosing an alternative source to petroleum when developing plastics, which entails choosing biopolymers instead of their synthetic counterparts.

Although “biopolymers” is sometimes used to describe biodegradable or biocompatible polymers (regardless of origin), in this blog we use this term to refer to only bio-derived polymers, i.e. polymers created from biomass. They are generated from renewable sources which also fix CO2 from the atmosphere and decrease greenhouse gas emissions. Many biopolymers are also biodegradable, providing more flexibility in disposing of products made with them and enabling recycling.

Types of biopolymers

There are three major classes of biopolymers, separated by their source and production method:

• Class A: Natural polymers obtained directly from biomass, such as starch, cellulose, proteins, amino acids and derivatives
• Class B: Polymers that are bio-synthesized using microorganisms and plants, or prepared directly from monomers that are predominantly bio-synthesized, such as polyhydroxyalkanoates (PHAs) and polylactic acid (PLA)
• Class C: Conventionally oil-based polymers prepared from alternative bio-sourced monomers, such as polyethylene and polyethylene terephthalate (PET)

Each class of biopolymer is suited to different commercial applications, whether it be packaging materials, agriculture, or biomaterials for surgery:

• Class A and B polymers are all biodegradable and are nearly all bio-based, but have inferior properties compared with oil-based plastics so are often used in combination with reinforcing fillers or impact modifiers
• Class C polymers are structurally similar to oil-based plastics, but are mostly not biodegradable and thus share the same disposal and recycling issues

The challenge to the increased uptake of biopolymers is cost. Initiatives aimed at improving fermentation yield and efficiency or integrating the production of biopolymers into food manufacturing plants or facilities with organic waste streams are attempting to take the edge off the high manufacturing costs, but this remains a key obstacle.

What are biopolymers currently used for?

Commercial bioplastics have been mainly used in packaging (Table 1). Starch and PLA are the most manufactured bioplastics, most likely due to their lower costs. PHAs, on the other hand, have high production costs and thus have been made in much lower quantities.

Table 1. Production and applications of top commercial biopolymers

It’s the ‘cool’ thing: Coca-Cola’s PlantBottle™

Sustainable innovation in biopolymers has been developing behind the scenes for decades, but these advances are not often newsworthy or publicly seen until top companies announce a new product. 

In the summer of 2015, the Coca-Cola Company unveiled its PlantBottle™ packaging - the world’s first plastic bottle made entirely from renewable resources. These bottles look, function, and recycle the same as bottles made from traditional plastic but have a significantly smaller impact on the planet by not touching petroleum. Announcements like this are encouraging for the continued development of biopolymers and their adoption in mainstream products worldwide.

Misconceptions vs facts about biopolymers

Public perception of biopolymers is also important for the wider implementation of these products; while the great benefits of these sustainable alternatives to traditional plastics are generally acknowledged, they have also been subject to criticism. Some of these criticisms have understandably arisen from misconceptions or confusion but others have come out of left field – Table 2 holds our opinions on some of the most frequently discussed topics.

Table 2. Misconceptions vs facts about biopolymers.

PBAT = polybutylene adipate terephthalate; PBS = polybutylene succinate; PLA = polylactic acid.

The biopolymer research landscape

Biopolymer research has been trending in recent years and was chosen as one of the top ten emerging technologies of the year 2019. Research and innovation leading up to this have been ongoing over the last two decades, as seen in the CAS Content Collection™ (Figure 1), constantly responding to fluctuations in oil prices and the general drive to increase sustainability and tackle climate change. The volumes of both journal publications and patents began to initially rise slowly but accelerated at a similar same pace from about 2009. Around 2014, the growth in patent publication volume slowed down considerably in contrast with the strong increase in journal publication numbers up to 2020.

As biopolymers are mainly developed as renewable alternatives to fossil-based plastics, substantial rises in the latter’s prices would increase biopolymers’ competitiveness, alongside boosting enthusiasm and confidence among researchers and inventors. Plastic prices are tightly linked to oil prices, which experienced substantial growth since the mid-2000s and an unprecedented sharp peak in 2008, which may potentially explain the inflection point, particularly visible in the patent publication number curve at around 2008. Oil prices plummeted after 2014, making biopolymers relatively more costly again, thus presumably discouraging inventors and causing the patent publication volume to level off in the exact same year.

Read our CAS Insights Report to find out more about the advantages, limitations, and popularity of the different classes of biopolymers, and how the research and development interest in these traditional plastic alternatives has changed over the last two decades.

Chemistry can be hazardous, and with so many people working in laboratories around the world, the impacts of even minor safety incidents add up. While individual organizations have strategies to prevent accidents, the safety data they gather is not always stored in an easily accessible way for day-to-day use. It’s just not feasible for scientists to read thousands of historical safety reports to find a mention of the compound they are about to use. 

People working in labs often see safety incidents happen more than once. I clearly recall an incident that occurred in one lab I worked in (at a previous employer) that triggered a change in our whole approach.  To carry out a reaction documented in a patent, trifluoroacetic acid had to be mixed with sodium borohydride to form a suspension of sodium trifluoroacetoxyborohydride. It turns out, that NaBH4 powder dissolves rapidly, resulting in an uncontrolled reaction that caused a fire. Pelletized NaBH4 would have reacted less vigorously.

The incident was communicated at a departmental safety briefing, but clearly the word had not gotten out, as the same thing occurred again four years later. I wondered, how can we capture safety lessons in a better way to ensure other scientists don’t have to learn the hard way? After some thought, it became clear that we need a practical way to integrate historical safety knowledge directly into our everyday laboratory workflows to prevent these types of avoidable incidents. But what could that look like in practical terms?  

Safety Information, When it’s Needed

To close this gap, we needed to work out a way to gather safety information and add it to the lab process without requiring an additional burdensome step for the chemist. There were three variables that had to be considered: the information being shared, when it was delivered and how it was delivered. 

We analyzed the workflow of our chemists using value-stream mapping to understand when they needed safety information and how this differed from when they were actually getting it. Typically, a chemist works by designing a reaction, procuring materials and finally synthesizing the product. It became clear that, to be most effective, safety information needed to be provided right before synthesizing the product,
 
We realized information from multiple sources, including the safety data sheet and institutional memory, could be fed into the Electronic Lab Notebook (ELN). Then, when a scientist planned to use certain compounds, the system could pop up saying, “Hey, be careful!” and provide relevant guidance, such as double-gloving or adding a safety screen. What’s more, the safety department could be notified by email if a chemist was planning on carrying out a potentially problematic reaction, so they could proactively advise on best practices and explore alternatives. 

Expanding the Idea to the Wider Community

Implementing this system eliminated repeat incidents; using the ELN to seamlessly flag safety concerns at the point of synthesis proved to be a successful strategy. This was great news.

Safety is a top priority in all chemistry laboratories for scientists at the bench, their department, and the organization as a whole. After successfully implementing this system, I wanted to expand the same strategy across the whole scientific community, so that all chemists could benefit. But, to make the system as effective as possible, more safety information was needed. Therefore, I looked to work with an organization that could create a system all pharmaceutical companies could use to share their safety data. The vision was to create a pre-competitive, crowd-sourcing tool for chemical safety information. 

The Pistoia Alliance is a global, not-for-profit membership organization working to facilitate innovation in life sciences research and development. In 2017, they initiated a pilot for a Chemical Safety Library (CSL), based on the system I had implemented previously, with the objective of gathering information on safety incidents submitted from across the chemical sector and providing the compiled database freely to the community to help prevent safety incidents. Upon release of the prototype, we discovered intense community interest in this type of data collection. But we also encountered reluctance to contribute incident information to the collection. Reasons varied, but included embarrassment, confidentiality concerns and data entry complexity.

The need was clear, and the more contributors that participated, the greater the impact would be. To expand the reach of this resource and address the limitations hindering participation, The Pistoia Alliance partnered with CAS, a division of the American Chemical Society that specializes in scientific information solutions, to deliver the new Pistoia Chemical Safety Library that was launched in October of last year. CAS, who developed and is hosting the new CSL platform, brings significant information management, technology and security expertise that allowed this new incarnation of the CSL to address the identified barriers. Data entry has been streamlined and simplified, and users can be confident that the data has been deidentified. The entire database is also available for organizations that want to integrate it for internal use, for example in an enterprise ELN. A CSL Advisory Panel, made up of representatives from the Pistoia Alliance, CAS and the wider chemical community, including Academia and Industry, also reviews the community entries and advises on policy and system improvements. 

The Community Needs You

I am very excited to see this expanded resource come to life. For the first time, we have the technology to readily gather and disseminate safety information from the entire global chemical community. If we truly come together to crowdsource this collection, we can reduce reaction incidents and make the lab a safer place for tens of thousands of chemists across the world.

The new CAS-hosted version of the CSL already has had over 8,000 users from 96 countries since it launched. The ball is now in your court. Check out the CSL to see how it can help you stay safe, but please don’t stop there. If you have been involved in an incident or near miss, enter it into the CSL to let the whole world learn from your experience.

Help make our community safer today! Share your safety data with the CSL