How Dichloromethane Affects Air, Water, and Soil Quality
There are two names of Dichloromethane one is methylene chloride and methylene. A lot of students get confused between these names and make a mistake of naming them separately. Methylene chloride is one of your colourless liquid that has a slightly sweet aroma.
If you have ever liked the smell of a newly painted wall, we are happy to tell you, and you have smelled the methylene chloride as it is used in lots of thinners because of its property of being a potent paint stripper. Today we are going to learn about the uses and the effects of dichloromethane. Also, we are going to discuss its chemical properties and what makes it dangerous for the environment.
Chemical Properties of Dichloromethane
For starters, let’s tell you one of the unknown names of the dichloromethane, it is also said to be refrigerant-30. You can find it naturally in earth’s oceans, volcanoes, wetlands. But even if you combine all of them still the more substantial part of it comes from the industrial process.
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If you are thinking about preparing it in your lab, you need to have chlorine gas with a temperature of 400 to 500 degrees celsius. Once you can get this temperature, you need to treat methane and chloromethane with it. But we suggest you not to do this experiment as it is dangerous. Because when you prepare dichloromethane it emits toxic fumes in the air.
There is no defined flashpoint, but it does produce some flammable vapour-air mixtures. Given below is the list of various properties of dichloromethane :
Boiling point of dichloromethane:- 39.6 °C;
Molecular weight:- 84.93 g·mol−1;
Density:- 1.3266 g/cm3;
Melting point:- 96.7 °C;
Solubility in water at room temperature:- 17.5 g/L
These are the most important properties that you need to know before you conduct any experiments with this compound.
Why Is Dichloromethane Dangerous?
Don’t be alarmed if someone says you should not be staying in a room that has been newly painted, just hours ago. This is because dichloromethane has been classified as a neurotoxin, meaning it can damage your central nervous system which presents in the brain. In addition to this, the high level of exposure to dichloromethane could lead to liver and lung cancer.
Following are the health dangers associated with dichloromethane :
If you inhale the compound, it can lead to shortness of breath and wheezing. Likewise, if you inhale a large amount of it can cause nausea and a feeling of dizziness.
Secondly, if it comes in contact with your skin, it can make your skin turn red, and the irritation will occur. On the other hand, if it in contact for a long time, it could eventually lead up to burning your skin.
In no way you should rub your eyes if you have dichloromethane on your hands, it could lead to permanent damage to your eyes.
Even a slightest of this liquid compound can cause a chemical burn in your eyes.
What to do if you were Exposed to Methylene Chloride?
If your eyes get in contact with the compound immediately flush both your eyes with water for at least 30 minutes. If you are wearing any lenses, remove them when cleaning and visit the doctor immediately.
Apply water and soap immediately to the surface of your skin which was in contact with the compound. If you are still feeling any irritation, consult a doctor.
When it comes to inhaling the fumes of methylene chloride, it is essential to seek the fresh air immediately. If you are having difficulty in breathing even after getting fresh air, visit your doctor as soon as possible.
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Methylene Chloride Uses in our Daily Lives
Here are some of the products that you see in your daily lives that contain dichloromethane in one form or the other.
As we mentioned earlier wall paints and paint strippers such as thinner use this compound as their ingredient, thus you get that sweet odour of paint.
Besides, it is also used as adhesives by hobbyists and sculptures in the form of cement to give intricate details to their creation.
In other cases, it is used as lubrication in automotive to keep its parts running smoothly.
Lastly, it is used by doctors for making medicines in a specific medical field.
FAQs on Dichloromethane Uses and Their Environmental Impact
1. What are the primary industrial applications of dichloromethane (DCM)?
Dichloromethane, also known as methylene chloride, is a versatile solvent with several key industrial applications. Its main uses include:
- Paint and Varnish Remover: It is highly effective at stripping paint and other coatings from various surfaces.
- Process Solvent: Used in the manufacturing of pharmaceuticals, plastics, and photographic films.
- Aerosol Propellant: It functions as a propellant and solvent in aerosol products like spray paints and insecticides.
- Metal Degreasing: Employed for cleaning and degreasing metal parts and surfaces in various industries.
- Food and Beverage Industry: Used as an extraction solvent, for example, in the decaffeination of coffee beans and tea leaves.
2. Why is dichloromethane considered an effective solvent in chemical and manufacturing processes?
Dichloromethane is valued as an effective solvent due to a combination of its chemical properties. Its ability to dissolve a wide array of organic compounds makes it highly versatile. Additionally, it has a low boiling point (39.6 °C), which means it is very volatile. This high volatility is advantageous in industrial processes because it allows the solvent to be easily and quickly removed by evaporation after it has served its purpose, leaving behind a pure product. Its relative chemical inertness and non-flammability at room temperature also contribute to its utility.
3. What are the key health risks for humans associated with dichloromethane exposure?
Exposure to dichloromethane poses significant health risks to humans, affecting the central nervous system. Even short-term exposure to low levels can cause dizziness, fatigue, nausea, and headaches. Higher levels of exposure are more dangerous because the human body metabolises dichloromethane into carbon monoxide (CO), which reduces the oxygen-carrying capacity of the blood. This can lead to severe health effects, including impaired vision and hearing, and at very high concentrations, it can cause suffocation, loss of consciousness, and even death. Long-term exposure is linked to liver and lung damage and it is considered a potential carcinogen.
4. How does dichloromethane impact the environment when it is released?
When released, dichloromethane's high volatility causes it to evaporate quickly and enter the atmosphere. While it does not significantly contribute to the depletion of the ozone layer, it is a Hazardous Air Pollutant (HAP). In the atmosphere, it can react with other pollutants to contribute to the formation of ground-level ozone (smog). If it enters soil or water, it can contaminate groundwater supplies. Although it breaks down in the environment over several months, its widespread and continuous use means it can be a persistent pollutant in industrial areas, posing a threat to aquatic life and ecosystems.
5. How do the chemical properties of dichloromethane make it such a powerful paint stripper?
Dichloromethane's effectiveness as a paint stripper is rooted in its molecular structure and physical properties. As a small and relatively polar molecule, it can efficiently penetrate the complex polymer matrix that constitutes a paint film. Once inside, it causes the polymer chains to swell, which physically lifts and blisters the paint layer. This swelling action breaks the adhesive bond between the paint and the underlying surface. Its volatility helps in the process by working its way under the loosened film, making it easy to scrape off. This mechanism of swelling the paint film from within is what makes it a much faster and more effective stripper than many other solvents.
6. If dichloromethane evaporates so quickly, why is it still considered a persistent health and environmental threat?
The persistence of the threat from dichloromethane, despite its high volatility, is a crucial concept. The danger lies in two main areas:
- Continuous Emission: While a single release evaporates, its widespread industrial use leads to continuous emissions. This means that even as older molecules break down in the atmosphere, new ones are constantly being introduced, maintaining a steady presence in the environment, particularly in urban and industrial areas.
- Toxic Metabolic Pathway: The most significant risk is not its environmental persistence but its biological effect. Once inhaled, its volatility allows it to be rapidly absorbed into the bloodstream. The danger is what happens next: the body converts it to carbon monoxide. This internal chemical conversion is what makes it so harmful, as CO binds to haemoglobin far more strongly than oxygen, leading to oxygen deprivation in tissues. Therefore, the threat is constantly renewed with each exposure, irrespective of how quickly it evaporates outdoors.
