We come into contact with chlorine every day, whether in our drinking water, in cleaning supplies or in our pools. In water treatment, chlorine has saved countless lives, but is it the best method for treating your pool? Here are seven chlorine facts that might challenge your perception of this common chemical and make you rethink your pool treatment method.
1) What are the most common uses for chlorine?
While chlorine is a chemical that can be toxic, some of its uses are critical to health and safety.
- Drinking water treatment: While we might not think much about this, 750 million people in the world lack access to safe water and 840,000 people die from water related illness each year. While chlorine can be harmful in excess amounts, the chlorine in our water keeps us from getting sick.
- Pool water treatment: A decades old method for pool water treatment, chlorine is no longer the only or best option. Why? Chlorine in typical pool levels doesn’t kill some common recreational water illnesses that can cause serious health problems.
- Consumer products: Chlorine is used to make many consumer products, including paper, paint, textiles and insecticides.
- PVC production: Chlorine is used to make this plastic found in products such as window frames, car interiors, water pipes and vinyl flooring.
- Pharmaceutical manufacturing: Chlorine is used in the manufacturing process of 85 percent of pharmaceuticals.
2) How much chlorine is in my drinking water?
The Environmental Protection Agency set a maximum limit for chlorine in drinking water to be 4 mg/L or 4 ppm. The World Health Organization states between 0.2 mg/L – 2.0 mg/L is a safe level for drinking water.
3) What level of chlorine does a typical pool contain?
A typical pool has between 3 and 5 ppm of chlorine, however, today there are options that enable you to reduce your pool chlorine to the same levels recommended by the WHO for drinking water, or even to completely chlorine free.
4) Why do chlorinated pools smell?
Chlorine in the pool reacts with organic substances like body oil, sweat, and urine to create disinfection byproducts, also commonly called chloramines. Disinfection byproducts have a very distinct smell — the pool chlorine smell — and they are harmful to human health, causing lung and eye irritation.
5) Why do chlorinated pools cause red eyes?
Again, it’s the disinfection byproducts produced from the reaction of chlorine and contaminants that cause your eyes to burn. If you are in an indoor pool with high chlorine levels, just standing on the pool deck can make your eyes burn.
Dry skin occurs after you swim because chlorine strips away the body’s oils and dries out the skin. Ask any competitive swimmer about dry skin, and he or she will tell you that lotion is essential after swimming (after a good shower to wash off any excess chlorine).
6) What happens if I’m exposed to too much chlorine?
Overexposure to chlorine can cause serious health problems and even death. According to the Centers for Disease Control, the following are symptoms of exposure to too much chlorine:
- Blurred vision
- Burning sensation in the nose, throat, and eyes
- Chest tightness
- Difficulty breathing / shortness of breath
- Fluid in the lungs
- Nausea and vomiting
- Watery eyes
- Burning pain and blisters on the skin (exposure to chlorine gas)
- Skin injuries similar to frostbite (exposure to liquid chlorine
Looking back on my swimming career and now as a coach, many swimmers — including my younger self — have these symptoms chronically. I always had a deep cough and my eyes and throat burned at practice. Recently, while coaching at an indoor pool notorious for high chlorine levels and poor air flow, two of the top swimmers had to withdraw due to chlorine/air quality-related issues. They were coughing and wheezing and had chest-tightness and difficulty breathing. These swimmers train outdoors and never had breathing issues in the past — a true testament to the harmful effects of the exposure to too much chlorine and DBPs.
7) Is chlorine bad for the environment?
It depends. According to the EPA, the effects of chlorine on the environment depend on how much chlorine is present and the length and frequency of exposure. Chlorine causes environmental harm at low levels and is especially harmful to organisms living in water and in soil. If people or companies are not disposing of chlorine safely, it can destroy the environment.