We will make a better society together.

[STEEL Talk] Stainless Steel Can Save Lives?

STEEL Talk presents to you interesting stories of Science, Technology, Energy, Environment, Life — and of course STEEL!

Medical dramas depict events and stories that happen at a hospital. In a scene inside the operating room, a doctor asks for a scalpel, a surgical instrument. Then, it is handed over instantly. The shining silver-looking surgical tools here seem threatening, but they’re actually the opposite once you get to know them. In fact, these steel-made tools play a crucial role in saving our lives.

“Cleanliness” and “hygiene” would be the two keywords that people are most interested in these days, due to the COVID-19 pandemic. The government, local authorities, corporates, and individuals are all doing their best to sanitize public places, such as hospitals, theaters, and public transportation facilities. The most needed and useful thing here is medical stainless steel known as “Surgical Steel.” POSCO Newsroom presents to you the secrets of the life-saving surgical steel.

l No More Germs! Stainless Steel Innovates the Medical Field

Before we learn more about surgical steel, let’s first go back to when stainless steel was invented.

It was only after the invention of stainless steel in 1913 that patients could get medical treatments in sanitary environments. In the past, many people lost their lives due to infections while undergoing medical treatment in an unsanitary environment.

The World Health Organization (WHO) has also cited that one of the most serious challenges that the modern healthcare industry faces is patient infections during treatment. Hundreds of millions of patients worldwide are exposed to diseases caused by infection every year, so maintaining a clean and healthy environment is paramount.

In fact, a publication by WHO in 2010 revealed that per 100 patients, seven in developed countries, and ten in developing countries suffer from healthcare acquired infections (HAIs). In high-income countries, about 30% of intensive care unit patients suffer from HAIs while the figure is two to three times higher in the case of low-income countries.

So what’s so special about surgical steel, or medical stainless steel? The answer is that it’s an excellent material in terms of hygiene! Surgical steel is resistant to corrosion, which means that there is no need to worry about any corrosion or degradation. Another advantage would be that it can be safely sterilized without any other side effects. Stainless steel is used in hospitals all around the world, in surgical knives, injection needles, and screws to hold broken bones, since it is safe to the human body — even inside!

What if we don’t use surgical steel? Rusty steel will penetrate your body, which can eventually cause tetanus, a terrible disease, or infection of various germs. Then how come stainless steel can be rust-free? Let’s look into the answer!

l Stainless Steel: The Secret Lies on the Passive Film!

Stainless steel is alloy steel made by adding chromium, carbon, nickel, manganese, etc. to iron (Fe). So, it is a highly corrosion-resistant material and versatile because it has excellent malleability to deform and it can withstand high external impact.

Stainless steel does not rust easily thanks to its special protective film called, ‘passive film,’ on the surface. This special protective film is chromium oxide (Cr2O3), which is formed spontaneously through the oxidation of chromium (Cr). Approximately 2nm (2mm divided by 1 million) in thickness, the film is so thin that it is invisible to bare eyes but it’s extremely solid and protects the base iron from oxidation. Even when a part of the film is destroyed due to a scratch, it quickly regenerates as the chromium meets oxygen again.

l Sterilizing Power, the Amazing Property of Stainless Steel!

In 2017, the International Stainless Steel Forum (ISSF) published a study result on its website demonstrating the amazing sterilizing power of stainless steel.

The study was jointly conducted by Manchester Metropolitan University in the UK and AgroParisTech, one of the most prestigious universities in the field of life and environmental science in France. The study explains how hygienic and crucial stainless steel is to use in environments where we are exposed to germs, like hospitals. Here is a brief explanation.

First, the researchers prepared two stainless steel samples. One was aged stainless steel (A), which was contaminated and cleaned repeatedly on purpose, and the other was newly-made stainless steel (B). Both sample (A) and (B) were exposed to ‘Staphylococcus aureus,’ a deadly bacteria responsible for food poisoning and infections, and ‘Pseudomonas aeruginosa,’ a bacteria difficult to treat. Both samples were then cleaned with the same disinfectant.

What was the difference between sample (A) and (B)? Surprisingly, the two samples showed almost no difference. Both samples were revealed to be 99.9 percent effective against Staphylococcus aureus and 97.6 percent effective against Pseudomonas aeruginosa. The experiment confirms that stainless steel can be used hygienically and safely over a long period of time.

Today, we learned about stainless steel that saves our lives. The scary-looking medical tools in the hospital might look differently to you now that you know about what surgical steel is. Stainless steel in the hospitals might look threatening, but remember! They’re actually our life-savers!