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  • What’s the difference between short-term and long-term chemical exposure levels?

    Acute or short-term exposure assumes that a person has been exposed to a chemical for a short period of time. Long term, also known as chronic, exposure assumes a person has been constantly exposed to a chemical for a lifetime, or approximately 70 years.

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  • How do the different parts of particulate matter (PM) fit together?

    The various parts of PM in the NEI are related as follows. PM10-FIL > PM25-FIL because PM10-FIL includes PM25-FIL PM25-PRI = PM25-FIL + PM-CON This equation only applies at the process level. Because some sources only can report PM2.5 (due to test method differences), this equation does not apply to…

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  • How does PM2.5 relate to PM species such as EC, OC, SO4, NO3, PMFINE, and DIESEL-PM25?

    Primary PM2.5 estimates are speciated into the five PM species in the NEI: elemental (black) carbon (EC), organic carbon (OC), nitrate (NO3), sulfate (SO4), and the remainder of PM25-PRI (PMFINE). Diesel engine PM25-PRI and PM10 emissions are also labeled as DIESEL-PM25 and DIESEL-PM10 for mobile source diesel engines. For all…

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  • Is our East Palestine City Park safe for activities?

    Yes. Results show that levels of dioxin and semi-volatile organic compounds are well below any levels that we would consider restricting activities, and all are either at or below typical background levels for soil in the United States. In addition, the village has cleaned all recreational equipment, including the pool…

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  • What is being done to control dust?

    Norfolk Southern contractors use engineering controls to reduce dust generated from cleanup activities and disturbed soil surfaces. All contaminated material leaving the derailment site is secured and tarped, and all contaminated material on site is tarped nightly. Trucks are decontaminated before they leave the site, and large water trucks are…

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  • Accidental releases from non-covered processes

    Should the owner or operator include accidental releases from processes containing listed substances below the threshold quantity in the five-year accident history required under the hazard assessment provisions of 40 CFR Part 68, Subpart B, and in the incident investigation requirements under 40 CFR Part 68, Subparts C and D…

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  • Do I have to report accidents that resulted in medical treatment?

    I had a release where several people were treated at the hospital and released; they attributed their symptoms to exposure. We do not believe that their symptoms were in fact the result of exposure to the released substance. Do we have to report these as offsite impacts? Yes, you should…

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  • Can I grow a garden at home or plant crops?

    Yes. You can continue to use your land as you normally would. Residential soil sampling results are within typical ranges for the area. Follow normal measures like peeling root vegetables and washing leafy greens.

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  • What are the terms used to describe the length of exposure to substances?

    Acute exposure is any contact with a substance that occurs once or for up to 14 days. Intermediate exposure is contact occurring for more than 14 days but less than one year. Chronic exposure is contact occurring for longer than one year.

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  • What is the definition of "offsite property damage?"

    I am working on the five-year accident history portion of the hazard assessment under the RMP. Section 68.42(a) tells me to include "all accidental releases from covered processes that resulted in deaths, injuries, or significant property damage on site, or known offsite deaths, injuries, evacuations, sheltering in place, property damage…

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  • When does the accident history's five-year period begin?

    The hazard assessment requirements under 40 CFR Part 68, Subpart B include provision of a five-year accident history, as specified at §68.42. When does the five-year period to be reported in the accident history begin? The five-year accident history must include information on all accidental releases from covered processes meeting…

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  • What is the definition of injury?

    Under the hazard assessment requirements of 40 CFR Part 68, Subpart B, an owner or operator must document a five-year accident history including all accidental releases from covered processes that resulted in deaths, injuries, or significant property damage on site, or known offsite deaths, injuries, evacuations, sheltering in place, property…

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  • Do Program Level 1 processes need to do five-year accident histories?

    What is the relationship between the accident history criteria for Program 1 and the five-year accident history? If my process is eligible for Program 1, do I still need to do a five-year accident history? The five-year accident history is an information collection requirement that is designed to provide data…

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  • Can smoke from the Canadian wildfires cause health concerns?

    Most healthy adults and children will recover quickly from smoke exposure and will not have long-lasting health effects. But people with chronic diseases, such as asthma, other lung disease, or cardiovascular disease are at greater risk of experiencing more severe health effects. Children, pregnant people, and people over 65 also…

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  • What is included in the emissions “Tiers”?

    The Tiers are assigned by a Source Classification Code (SCC), which has the most detail about the emissions processes that generate the emissions. The full list of SCCs, their associated Tiers, and the SCC descriptions is available online at https://ofmpub.epa.gov/sccwebservices/sccsearch/ .

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