Ah yes… bright sun, warm temps, lazy rivers and the sweet smell of chlorine — that’s when you know it’s summer. But there’s more to the notorious CI #17 than just its role in disinfecting swimming pools. Chlorine chemistry is the building block for a staggering amount of manufactured goods including pesticides, paper, pharmaceuticals, paints and more. Here’s more on our chemical of the week:
The 101:
On the periodic table, chlorine is in a group of halogens — or elements that form salts when combined with metal. It’s one of the most abundant chemicals on earth. At room temperature it’s a yellow-green gas that’s highly toxic to humans.
Chlorine was formally discovered in 1774 when a Swedish scientist Carl Wilhelm Scheele accidentally produced it by releasing a few drops of hydrochloric acid onto a piece of manganese dioxide. But for decades scientists thought it was a compound of oxygen — until 1810 when an English chemist named Sir Humphry Davy recognized it as a pure element. By then the chemical was already making its way into mass manufacturing.
‘The Element of Surprise’
In the 18th century a French textile producer whipped up a bleaching agent by dissolving chlorine in water — a process he soon improved by adding the chlorine to a caustic potash solution, according to The Chlorine Institute.
Pretty soon the bleaching solution was sweeping through the Western world and technology was evolving to produce it on a bigger scale.
Today chlorine is one of the most produced chemicals in the U.S. The American Chemistry Council calls it “the element of surprise” because of its wide-scale use in manufacturing. According to the ACC, chlorine chemistry is an essential building block for more than 90 percent of pharmaceuticals, and is used in everything from common painkillers to surgical stitches and medical devices.
Chlorine chemistry is also utilized in just about every major industry in too many products to list — from light-weight cars, to 80 percent of crop protection compounds, to paints, solar panels, household cleaners and even bullet-proof vests for the military.
Fun Facts:
- According to Live Science: “Some frogs have a chlorine compound in their skin that is a very strong painkiller, according to Los Alamos National Laboratory. The compound, called epibatidine, has no side effects in small doses, but in large doses, it is fatal to humans.”
- Chlorine can show up in chicken because many U.S. factory farms bathe chicken in the chemical to help decrease fecal contamination.
- The chlorine industry contributes more than $46 billion annually to the North American economy, according to the ACC.
Myth Busting at The Swimming Pool:
- When it comes to pools, chlorine gets a bad rep. Those zombie red eyes you sometimes have after taking a dip? They’re not just from chlorine. According to the Centers for Disease Control and Prevention, they’re actually caused by — prepare for an ick factor — pee, poop and other human grossness. When chlorine binds with nitrogen in urine it forms a derivative of ammonia called chloramine, which can cause red eyes, runny noses and coughing.
- That chemical aroma at the pool? It’s also not just chlorine, but chlorine reacting with other substances in the water. According to the CDC, the more pee, poop and dirt in the pool, the worse it smells.
- If you also believe that swimming in chlorinated pools can turn blonde hair into unflattering green locks, you’d be wrong again. The real culprit is copper, which is released into the water through old pipes or with other chemicals that are added to fight algae. An acid base imbalance can also be to blame. According to one local news report: “If the pool's pH is too high, the positively charged copper particles floating in the water look for anything that has a negative charge (opposites attract) and that includes your silky strands.”
- Too much chlorine, however, can wreak havoc. Just a few weeks ago about 25 kids at a North Carolina pool got sick with nausea and vomiting after too much chlorine was added to a public pool. And while that kind of news might make you want to stay out of the water or avoid drinking water disinfected with chlorine, consider this: Without it, bacteria such as E. coli can thrive. In 2000, seven people died and more than 2,300 fell ill after the water supply in a town in Ontario got contaminated by E. coli and other bacteria. Officials said that proper chlorine levels could have prevented the disaster.
Not-so-Fun Facts
- Like many chemicals, chlorine has a dark side. Some studies have attempted to show that drinking chlorinated water can lead to an increased risk for cancer. But the chemical has not been labeled a carcinogen by public health officials.
- Frequent trips to the pool have also been linked to higher asthma rates among children and some scientists believe that higher rates of exposure to chlorine in cleaning products are part of the catalyst behind increased allergies over the last 50 years.
- Worst of all, chlorine has been used in chemical weapons since World War I when Germans began producing a chlorine gas known as bertholite. Because chlorine can react with water in the mucosa of the lungs and form hydrochloric acid, the gas can be lethal. More recently, chlorine bombs were used by insurgents in the Iraq War and in the Syrian Civil War, and now many have alleged that ISIS has gotten its hands on ‘chlorine-filled rockets’ that they’re using to attack civilians. Days ago, reports emerged that ISIS also has “industrial grade” gas masks, which has many worrying that they’re readying themselves for large-scale chemical warefare.
Have an idea for a “Chemical of The Week?” Shout out to [email protected] or Tweet me @MeaganChemInfo.
