Emissions standard

Do you know how cars and trucks work? They have engines that run on fuel, like gasoline or diesel. When they burn that fuel, they make something called emissions.

Now, as you might imagine, these emissions are not good for the air we breathe. They can make the air dirty and unhealthy. So, to try and keep the air cleaner, governments around the world have set what they call "emissions standards".

An emissions standard is a rule that says how much of certain types of emissions a vehicle is allowed to produce. For example, one standard might say that a car can't create too much carbon monoxide, which is a dangerous gas that can hurt people.

To make sure that car companies follow these standards, there are tests that measure the amount of different emissions a car makes. If a car company produces a car that makes too much of a certain type of emission, they can be penalized or not allowed to sell their cars in certain places.

So, in short, emissions standards are rules that try to make sure our cars and trucks don't make the air we breathe too dirty, and that car companies follow those rules so we can all stay healthy.