CHEMICAL PROFILES|References for Scorecard Risk Assessment Values

ATSDR: Agency For Toxic Substances and Disease Registry. Minimum Risk Levels, January 2004.

California EPA and California Air Pollution Control Officers Association. Air Toxics Hotspots Program Risk Assessment Guidance: Revised 1992 Risk Assessment Guidance. Office of Environmental Health Hazard Assessment, CalEPA, Berkeley, CA. December 1994.

EDF-CalEPA: Scorecard's noncancer inhalation Reference Concentration for lead and lead compounds is based on a proposed REL developed by CalEPA's Air Toxicology and Epidemiology Section. Utilizing a sophisticated model that takes into account the current distribution of blood lead levels in California children and relates increased ambient air lead exposures to the increase in numbers of children predicted to have blood lead levels exceeding the CDC guideline of 10 ug/dL, ATES proposed a REL for lead of 0.15 ug/m3. California Air Resources Board. Proposed Identification of Inorganic Lead as a Toxic Air Contaminant, Part B, Health Assessment. May 6, 1994 Draft of Section 6: Development of Reference Exposure Levels. This proposed REL was derived to protect children aged 1-6 from the adverse neurotoxic effects of lead exposures. Using exposure parameters appropriate for this age cohort (a time-averaged breathing rate of 8.7m3/d and bodyweight of 16.6 kg), this REL was converted to an RfD of 7.86E-5 mg/kg-d for use in the Scorecard.

EDF-EPA: Some PCB and dioxin congeners have been assigned potencies based on application of International Toxic Equivalency Factors (ITEFs) to EPA potency values for 2,3,7,8-TCDD:
Van den Berg et al., 1998. Toxic Equivalency Factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife. Environmental Health Perspective, 106 (12), 775-792.
Ahlborg, U; Becking, GC; Birnbaum, LS; et al., 1994. Toxic equivalency factors for dioxin-like PCBs: report on a WHO-ECEH and IPCS consultation, Dec. 1993. Chemosphere 28(6):1049-1067.

The polycyclic organic matter chemical grouping has been assigned an inhalation cancer potency based on: Interim methodology to give estimates of potency for Cumulative Exposure Project POM inventories. August 5, 1998 Memorandum from JC Caldwell (OAQPS/OAR) to TJ Woodruff and DA Axelrad (Office of Policy).

HEAST: EPA, Office of Research and Development. Health Effects Assessment Summary Tables. July 1997.

HWIR: EPA, Office of Solid Waste. Hazardous Waste Identification Rule Technical Support Documents: Risk Assessment for Human and Ecological Receptors. Initial (8/95) and Supplemental (11/95) Technical Support Documents. OSW, Washington, DC. Obtained as an electronic file.

IRIS: EPA, National Center for Environmental Assessment. Integrated Risk Information System.

OEHHA-CAN: CalEPA, Office of Environmental Health Hazard Assessment. Air Toxics Hot Spots Program Risk Assessment Guidelines. Part II. Technical Support Document for Describing Available Cancer Potency Factors (December 2002).
CalEPA, Office of Environmental Health Hazard Assessment. Adoption of a Unit Risk Value for Naphthalene (August 2004).

OEHHA-CREL: California EPA, Office of Environmental Health Hazard Assessment. Air Toxics Hot Spots Program Risk Assessment Guidelines, Part III: Technical Support Document "Determination of Noncancer Chronic Reference Exposure Levels". Includes all Chronic Reference Exposure Levels (CRELs) adopted by OEHHA as of August 2003 (, plus draft CRELS proposed through March 2004 (

OEHHA-NSRL: California EPA, Office of Environmental Health Hazard Assessment. Proposition 65 Status Report Safe Harbor Levels: No Significant Risk levels for Carcinogens and Maximum Allowable Dose Levels for Chemicals Causing Reproductive Toxicity (June 2004).

OEHHA-TCD: California Environmental Protection Agency, Office of Environmental Health Hazard Assessment. Toxicity Criteria Database - OEHHA Cancer Potency Values.

OPP-CAN: EPA, Office of Pesticide Programs. List of Chemicals Evaluated for Carcinogenic Potential (5/10/2002). OPP, Washington, DC.

OPP-RfD: US EPA, Office of Pesticide Programs. RfD Tracking Report (2/97). OPP, Washington, DC. Obtained as an electronic file (ProdVol.dbf); available online at

SCDM: EPA, Office of Emergency Response and Remediation. Superfund Chemical Data Matrix.

TRI: EPA, Office of Pollution Prevention and Toxics. TRI Risk-Screening Environmental Indicators Version 2.0. January 2001. See Technical Appendix A - Available Toxicity Data for TRI Chemicals of the RSEI User's Manual. (Appendix A last updated Feb. 2002).