What is the one hour ozone standard?

0.12 parts per million
Summary. A revised ozone standard (0.12 parts per million (ppm) over a one hour period) was promulgated by the Environmental Protection Agency (EPA) in 1978. A violation occurs when an area exceeds the ozone standard more than three times in three years at a given monitor.

What is the Naaqs for ozone?

0.075 parts per million
The American Petroleum Institute (API) supports the option EPA included in the proposal to retain the current primary National Ambient Air Quality Standards (NAAQS) for ozone at the level of 0.075 parts per million (ppm).

What does Naaqs revoked mean?

Counties in Revoked NAAQS areas have “NAAQS revoked” appended to the NAAQS description. A blank cell for a year indicates either the area the county is in: 1) was not designated nonattainment for that NAAQS, 2) had been redesignated to maintenance, or 3) is for a NAAQS that was revoked prior to that year.

What is the current US allowable level Naaqs for CO?

9 ppm

Pollutant [links to historical tables of NAAQS reviews] Level
Carbon Monoxide (CO) 9 ppm
35 ppm
Lead (Pb) 0.15 μg/m3 (1)
Nitrogen Dioxide (NO2) 100 ppb

What is an unhealthy ozone level?

Good (0-50) No health impacts are expected when air quality is in this range. Moderate (51-100) Unusually sensitive people should consider limiting prolonged outdoor exertion. Unhealthy for. Sensitive Groups. (101-150)

What is normal ozone level?

Based on extensive scientific evidence about the effects of ozone on public health and welfare, on October 1, 2015, EPA strengthened the ground-level ozone standard to 0.070 ppm, averaged over an 8-hour period.

What is the federal Clean Air Act?

The Clean Air Act is the law that defines EPA’s responsibilities for protecting and improving the nation’s air quality and the stratospheric ozone layer. The last major change in the law, the Clean Air Act Amendments of 1990, was enacted by Congress in 1990.

What is an Aqcr?

An interstate or intrastate area designated by the U.S. Environmental Protection Agency (EPA) for the attainment and maintenance of National Ambient Air Quality Standards (NAAQS).

What is the EPA standard for carbon monoxide?

EPA has defined the national ambient air quality standard (NAAQS) for carbon monoxide as nine parts per million averaged over an eight-hour period, and this threshold cannot be exceeded more than once a year or an area would be violating the standard.

What two pollutants pose the greatest threat to human?

Ground-level ozone and airborne particles are the two pollutants that pose the greatest threat to human health in this country.

Where is the bad ozone located?

“Bad” ozone is found in the troposphere, the layer nearest the ground. Tropospheric ozone is a harmful pollutant which forms when sunlight alters various chemicals emitted by humans. “Good” ozone forms in the stratosphere, the next higher layer where some jet planes fly.