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Section 112(f)-"Residual Risk"

The Standards to Protect Health and the Environment (112(f) (known as the "Residual Risk" Program): Requires the EPA to assess the risk to public health remaining after the implementation of NESHAP. If the "residual risk" for a source category does not protect public health with "an ample margin of safety," the EPA must promulgate health-based standards for that source category to further reduce HAP emissions. The EPA is required to set more stringent standards if necessary to prevent adverse environmental effects (considering energy, costs and other relevant factors). The EPA must set residual risk standards within 9 years after promulgation of each NESHAP in the 2-year group (see subsection (e) for "group" explanation) and within 8 years for all other groups.

The risk assessment contact for 112(f) is Roy Smith (smith.roy@epa.gov) and for the Residual Risk Report to Congress , Deirdre Murphy  (murphy.deirdre@epa.gov) .

April 1998 Draft Residual Report to Congress
(PDF file, 1214 K)
March 1999 Residual Report to Congress (EPA 453/R-99-001)
(PDF file, 2336 K)

The full text of CAA Section 112(f) follows:

(f) Standard To Protect Health and the Environment.-  
     (1)  Report.- Not  later  than 6  years  after the  date  of
  enactment  of the Clean Air Act Amendments of 1990 the Adminis-
  trator shall  investigate and  report, after  consultation with
  the Surgeon  General and after opportunity  for public comment,
  to Congress on -  
       (A)  methods  of calculating  the  risk  to public  health
     remaining,  or likely  to  remain, from  sources subject  to
     regulation  under  this  section after  the  application  of
     standards under subsection (d); 
       (B)  the  public  health significance  of  such  estimated
     remaining  risk and  the  technologically  and  commercially
     available methods and costs of reducing such risks; 
       (C)  the actual  health  effects with  respect to  persons
     living  in   the   vicinity  of   sources,   any   available
     epidemiological or other health  studies, risks presented by
     background  concentrations of hazardous  air pollutants, any
     uncertainties in risk assessment methodology or other health
     assessment   technique,   and   any   negative   health   or
     environmental consequences to  the community  of efforts  to
     reduce such risks; and
       (D)  recommendations  as  to  legislation  regarding  such
     remaining risk.
  (2) Emission standards.-  
       (A) If Congress does not act on any recommendation submit-
     ted under  paragraph (1), the Administrator  shall, within 8
     years after  promulgation of standards for  each category or
     subcate-gory of  sources pursuant to subsection (d), promul-
     gate   stand-ards  for  such   category  or  subcategory  if
     promulgation  of  such standards  is  required  in order  to
     provide  an ample margin of safety  to protect public health
     in  accordance with this  sec-tion (as in  effect before the
     date of enactment of  the Clean Air Act Amendments  of 1990)
     or  to  prevent, taking  into consid-eration  costs, energy,
     safety, and other relevant factors, an adverse environmental
     effect. Emission standards promulgated under this subsection
     shall provide  an ample margin  of safety to  protect public
     health in accordance
     with this section (as in effect before the date of enactment
     of  the  Clean  Air  Act  Amendments  of  1990), unless  the
     Administrator determines that  a more stringent standard  is
     necessary  to  prevent,  taking  into  consideration  costs,
     energy,  safety,  and  other  relevant  factors, an  adverse
     environmental  effect. If standards  promulgated pursuant to
     subsection (d)  and applicable to a  category or subcategory
     of sources  emitting a pollutant (or  pollutants) classified
     as a  known, probable  or possible  human carcinogen  do not
     reduce lifetime  excess cancer risks to  the individual most
     exposed to  emissions  from  a  source in  the  category  or
     subcategory   to  less   than  one   in  one   million,  the
     Administrator   shall   promulgate   standards  under   this
     subsection for such source category. 
       (B) Nothing in subparagraph (A) or in  any other provision
     of this section shall be construed as affecting, or applying
     to the Administrator's interpretation of this section, as in
     effect before the  date of  enactment of the  Clean Air  Act
     Amendments  of 1990 and set forth in the Federal Register of
     September 14, 1989 (54 Federal Register 38044). 
       (C) The  Administrator shall  determine whether or  not to
     promulgate such standards and,  if the Administrator decides
     to promulgate such standards, shall promulgate the standards
     8 years after promulgation of the standards under subsection
     (d) for  each source  category or subcategory  concerned. In
     the case of categories  or subcategories for which standards
     under subsection (d) are required to be promulgated within 2
     years  after  the date  of enactment  of  the Clean  Air Act
     Amendments  of 1990,  the Administrator  shall have  9 years
     after promulgation of the  standards under subsection (d) to
     make the determination under  the preceding sentence and, if
     required, to promulgate the standards under this paragraph. 
     (3)  Effective date.-    Any  emission standard  established
  pursuant  to  this  subsection  shall  become  effective   upon
  promulgation. 
     (4) Prohibition.- No air pollutant to which a standard under
  this  subsection applies  may  be emitted  from any  stationary
  source in violation of  such standard, except that in  the case
  of an existing source -  
          (A) such standard  shall not apply until 90  days after
       its effective date, and 
          (B)  the Administrator  may grant  a waiver  permitting
       such  source a period of up to 2 years after the effective
       date  of a  standard to  comply with  the standard  if the
       Administrator finds that such  period is necessary for the
       installation  of controls  and  that steps  will be  taken
       during  the period of the waiver to assure that the health
       of persons will be protected from imminent endangerment. 
     (5)  Area sources.-  The Administrator shall not be required
  to  conduct  any review  under  this  subsection or  promulgate
  emission limitations under this  subsection for any category or
  subcate-gory  of  area  sources  that  is  listed  pursuant  to
  subsection
  (c)(3)  and  for  which  an emission  standard  is  promulgated
  pursuant to subsection (d)(5). 
     (6) Unique chemical substances.-   In establishing standards
  for  the  control  of  unique  chemical  substances  of  listed
  pollutants  without  CAS  numbers  under this  subsection,  the
  Administrator shall  establish such  standards with respect  to
  the health and environmental effects of the substances actually
  emitted by sources and direct transformation byproducts of such
  emissions in the categories and subcategories. 
  

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