Methane alone isn't a toxic substance, although it is highly flammable. You can also die by asphyxiation if a leak occurs in a place that isn't very well ventilated, as it can deprive you of oxygen. Methane gas does become poisonous, however, under the right circumstances and when mixed with certain gases. Unfortunately, methane gas poisoning occurs more often than you think.
In order to recognize the symptoms of methane gas poisoning, you first have to recognize the risk of your getting poisoned. Consider the three ways methane can get into your system - inhalation, ingestion, and touch.
Methane gas can be introduced into your system if a gas leak in your building releases it into the air you breathe. You can also inhale it if you pass by a sewer, a septic tank, or a compost heap.
Methane also has a chance of entering your body through the food you eat. While unlikely, it's possible for underground methane to seep through the soil and into water reservoirs. Dirty eating habits can also lead to methane-contaminated soil to get into your food. Thankfully, when it comes to these cases, the levels of methane are low and have no significant effects on the human body.
Methane gas has trouble penetrating the skin, but in the off chance that it does, it'll flow quickly through your body and be purged from your system via breathing, blood circulation, and urinating.
As you can see, the odds of you contracting methane gas poisoning are quite low, but it doesn't erase the fact that it does happen. Methane poisoning is not to be ignored, as the dangers that serious cases present can prove to be fatal. It is important, therefore, to recognize the signs and symptoms of methane gas poisoning.
As methane gas tends to displace the oxygen in your system, methane gas poisoning will likely show signs similar to that of suffocation. Early symptoms may include headaches and dizziness. This is because your brain is being deprived of the oxygen it needs to function properly. Some people may not notice these symptoms, however, and will only realize something's wrong when they begin gasping for air. In cases like these, it isn't uncommon for people to collapse from the lack of oxygen. If this happens to you, and you aren't brought to an open, well-ventilated area, you'll continue to asphyxiate and ultimately perish.
Methane also creates another dangerous byproduct - carbon monoxide. Depending on the concentration of carbon monoxide in the air you breathe, you could be dead in less than three minutes. In common cases, however, you'll develop headaches and nausea within twenty minutes to an hour. The damage carbon monoxide can do to your body can even reach your heart. Extremely serious cases, however, will cause you to hallucinate. It can cause convulsions, an irregular heartbeat, and high blood pressure as well.
What is difficult about diagnosing methane gas poisoning is that most people simply brush off the signs, as symptoms of other conditions, like depression, migraine, and chronic fatigue. While the chances of you getting poisoned by methane gas are very, very low, it's still best to be aware, especially when your health is concerned.