I was shopping with a friend recently and she had castor oil on her grocery list. That gave me pause. From my early days as a retail pharmacist, I remembered that castor oil was sold over the counter as a laxative. Today, there are more effective and safer laxatives on the market.

As I questioned her about her choice, she said that she used castor oil on her skin to remove blemishes that crop up from time to time. That reminded me that castor oil was used long ago to soften dry skin and to moisturize hair, also uses that have gone out of favor for more effective and safer products.

At any rate, I went in search of castor oil, but found it difficult to find. Even the pharmacist on duty scratched his head at my request, “In what aisle would I find castor oil?” It was indeed stocked in his store—in a section that should have been labeled “and everything else that no one knows what to do with.”

Since becoming a murder mystery writer, I’ve learned that the castor bean is the primary source of the chemical ricin and have done research about using this chemical in a storyline as a weapon of mass destruction.

Ricin is one of the most poisonous chemicals on Earth. It’s a highly lethal poison found naturally in castor beans and there is no known antidote.

The chemical ricin is a naturally occurring protein from the castor oil plant. It’s extracted from the waste matter (called the “mash”) left over from processing castor beans into castor oil. FORTUNATELY (for my friend at least), the toxic protein is denatured and deactivated during the heating process to extract the oil.

Ricin can be removed from castor beans, however, and made into a powder, a mist, a pellet, or it can be dissolved in water.

It’s important to point out that commercial castor oil contains NONE of the toxic proteins from the mash and is a safe product to use.

The only uses that I found for ricin extracted from the waste mash were as an experimental drug to kill cancer cells (still only experimental) and for use as a chemical weapon!

The medium lethal oral dose of ricin is a little over 3mg. That means a dose of pure ricin about the size of a few grains of table salt can kill an adult human. If the chemical is injected or inhaled, the dose is even lower, about 1.5mg to kill a 150-lb adult. It’s been said that a lethal dose of castor seeds for adults is about four to eight seeds.

As with most chemicals, various factors determine how sick a person will become when exposed, and if it will be fatal. These include how much ricin a person is exposed to, how long the exposure lasts, and what exposure method is used. For instance, inhalation and injection are almost always fatal, but ingestion may only make a person extremely sick, especially if medical support is rapidly provided.

The purity of ricin can also significantly affect how lethal a dose is. When the chemical is purified by special, technically advanced processes, the substance is deadlier than “back kitchen” processing.

Ricin kills by infecting our cellular structures and blocking their ability to synthesize their own proteins. When a cell cannot make protein, key bodily functions shut down and progressive organ failure usually results in death. Even when a person survives ricin poisoning, permanent organ damage often results.

The progression to death is extremely unpleasant. Usually, humans exposed to a lethal oral dose will experience severe vomiting and diarrhea within six hours of exposure and this results in serious dehydration. Eventually, the kidneys, liver and pancreas fail. Death follows soon after.

Inhalation of ricin, on the other hand, produces different effects since the poison interacts with other body parts. Inhaled ricin causes a vicious, bloody cough and the lungs fill with fluid. Eventually, the lungs become so fluid filled that the victim loses the ability to breathe. In effect, the person drowns in the body’s own fluids.

Lethal doses of ricin that are injected usually result in intense flu-like symptoms, swelling around the injection site, and eventual progressive organ failure as the poison circulates throughout the body.

Death from inhalation or injection occurs in about three to five days after contact, but it could be as rapid as 36 to 72 hours. And the death is an agonizing one.

Unfortunately, various techniques for making this poison are readily available on the Internet, and periodically this method of murder is used in terror plots against government or corporate personnel. Therefore, murder by ricin can be categorized as a murder “ripped from the headlines,” making it an interesting and often used lethal weapon on TV, in the movies and in novels.

Of course, if you’ve been reading my past blogs, you’ll realize that there are much more imaginative methods for killing off characters in your novels, and I’ll discuss more of them in future blogs.

Thoughts? Comments? I’d love to hear them!