Search results
Results from the WOW.Com Content Network
Toxic: a chemical that has a median lethal concentration (LC 50) in air of more than 200 parts per million (ppm) but not more than 2,000 parts per million by volume of gas or vapor, or more than 2 milligrams per liter but not more than 20 milligrams per liter of mist, fume or dust, when administered by continuous inhalation for 1 hour (or less if death occurs within 1 hour) to albino rats ...
Toxic gases, by contrast, cause death by other mechanisms, such as competing with oxygen on the cellular level (e.g. carbon monoxide) or directly damaging the respiratory system (e.g. phosgene). Far smaller quantities of these are deadly. Notable examples of asphyxiant gases are methane, [1] nitrogen, argon, helium, butane and propane
Methane (US: / ˈ m ɛ θ eɪ n / METH-ayn, UK: / ˈ m iː θ eɪ n / MEE-thayn) is a chemical compound with the chemical formula CH 4 (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas.
The world saw a record jump in levels of methane in the atmosphere last year as the main heat-trapping greenhouse gases reached new highs, UN experts said. ... of the total carbon emissions from ...
Global methane emissions have risen faster than ever over the last 5 years, with at least two-thirds of annual methane emissions coming from human activities.
[5]: 82 Methane's radiative forcing (RF) of climate is direct, [6]: 2 and it is the second largest contributor to human-caused climate forcing in the historical period. [6]: 2 Methane is a major source of water vapour in the stratosphere through oxidation; [7] and water vapour adds about 15% to methane's radiative forcing effect. [8]
That's because methane's biggest emissions comes from wetlands, which during a La Nina is wetter in much of the tropics, creating more microbes in the lush growth to release methane, Lan said.
Methanol has a moderate to high toxicity in humans. As little as 10 mL of pure methanol when drunk is metabolized into formic acid , which can cause permanent blindness by destruction of the optic nerve . 15 mL is potentially fatal, [ 1 ] although the median lethal dose is typically 100 mL (3.4 fl oz) (i.e. 1–2 mL/kg body weight of pure ...