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Minimal Risk Levels (MRLs) for Hazardous Substances


Minimal Risk Levels (MRLs)
for
Hazardous Substances

MRL List PDF Print MRL List, 41 KB

Narrative

The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) [42 U.S.C. 9604 et seq.], as amended by the Superfund Amendments and Reauthorization Act (SARA) [Pub. L. 99 499], requires that the Agency for Toxic Substances and Disease Registry (ATSDR) develop jointly with the U.S. Environmental Protection Agency (EPA), in order of priority, a list of hazardous substances most commonly found at facilities on the CERCLA National Priorities List (NPL) (42 U.S.C. 9604(i)(2)); prepare toxicological profiles for each substance included on the priority list of hazardous substances, and to ascertain significant human exposure levels (SHELs) for hazardous substances in the environment, and the associated acute, subacute, and chronic health effects (42 U.S.C. 9604(i)(3)); and assure the initiation of a research program to fill identified data needs associated with the substances (42 U.S.C. 9604(i)(5)).

The ATSDR Minimal Risk Levels (MRLs) were developed as an initial response to the mandate. Following discussions with scientists within the Department of Health and Human Services (HHS) and the EPA, ATSDR chose to adopt a practice similar to that of the EPA's Reference Dose (RfD) and Reference Concentration (RfC) for deriving substance specific health guidance levels for non neoplastic endpoints. An MRL is an estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse noncancer health effects over a specified duration of exposure. These substance specific estimates, which are intended to serve as screening levels, are used by ATSDR health assessors and other responders to identify contaminants and potential health effects that may be of concern at hazardous waste sites. It is important to note that MRLs are not intended to define clean up or action levels for ATSDR or other Agencies.

The toxicological profiles include an examination, summary, and interpretation of available toxicological information and epidemiologic evaluations of a hazardous substance. During the development of toxicological profiles, MRLs are derived when ATSDR determines that reliable and sufficient data exist to identify the target organ(s) of effect or the most sensitive health effect(s) for a specific duration for a given route of exposure to the substance. MRLs are based on noncancer health effects only and are not based on a consideration of cancer effects. Inhalation MRLs are exposure concentrations expressed in units of parts per million (ppm) for gases and volatiles, or milligrams per cubic meter (mg/m3) for particles. Oral MRLs are expressed as daily human doses in units of milligrams per kilogram per day (mg/kg/day). Radiation MRLs are expressed as external exposures in units of millisieverts.

ATSDR uses the no observed adverse effect level/uncertainty factor (NOAEL/UF) approach to derive MRLs for hazardous substances. They are set below levels that, based on current information, might cause adverse health effects in the people most sensitive to such substance induced effects. MRLs are derived for acute (1-14 days), intermediate (>14 - 364 days), and chronic (365 days and longer) exposure durations, and for the oral and inhalation routes of exposure. Currently MRLs for the dermal route of exposure are not derived because ATSDR has not yet identified a method suitable for this route of exposure. MRLs are generally based on the most sensitive substance-induced end point considered to be of relevance to humans. ATSDR does not use serious health effects (such as irreparable damage to the liver or kidneys, or birth defects) as a basis for establishing MRLs. Exposure to a level above the MRL does not mean that adverse health effects will occur.

MRLs are intended to serve as a screening tool to help public health professionals decide where to look more closely. They may also be viewed as a mechanism to identify those hazardous waste sites that are not expected to cause adverse health effects. Most MRLs contain some degree of uncertainty because of the lack of precise toxicological information on the people who might be most sensitive (e.g., infants, elderly, and nutritionally or immunologically compromised) to effects of hazardous substances. ATSDR uses a conservative (i.e., protective) approach to address these uncertainties consistent with the public health principle of prevention. Although human data are preferred, MRLs often must be based on animal studies because relevant human studies are lacking. In the absence of evidence to the contrary, ATSDR assumes that humans are more sensitive than animals to the effects of hazardous substances that certain persons may be particularly sensitive. Thus the resulting MRL may be as much as a hundredfold below levels shown to be nontoxic in laboratory animals. When adequate information is available, physiologically based pharmacokinetic (PBPK) modeling and benchmark dose (BMD) modeling have also been used as an adjunct to the NOAEL/UF approach in deriving MRLs.

Proposed MRLs undergo a rigorous review process. They are reviewed by the Health Effects/MRL Workgroup within the Division of Toxicology and Environmental Medicine; and expert panel of external peer reviewers; the agency wide MRL Workgroup, with participation from other federal agencies, including EPA; and are submitted for public comment through the toxicological profile public comment period. Each MRL is subject to change as new information becomes available concomitant with updating the toxicological profile of the substance. MRLs in the most recent toxicological profiles supersede previously published levels. To date, 137 inhalation MRLs, 226 oral MRLs and 8 external radiation MRLs have been derived. A listing of the current published MRLs by route and duration of exposure is provided as follows.

ATSDR Contact Person for MRLs:

Dr. Selene Chou
Division of Toxicology and Environmental Medicine
Agency for Toxic Substances and Disease Registry
1600 Clifton Road, Mailstop F32
Atlanta, Georgia 30333
Telephone: 770-488-3357
E-Mail: cjc3@cdc.gov

MRL List

ATSDR Minimal Risk Levels (MRLs)
November 2007

                 
Name Route Duration MRL Factors Endpoint Draft/Final Cover Date CAS Number
                 
                 
ACENAPHTHENE Oral Int. 0.6 mg/kg/day 300 Hepatic Final 08/95 000083-32-9
                 
ACETONE Inh. Acute 26 ppm 9 Neurol. Final 05/94 000067-64-1
    Int. 13 ppm 100 Neurol.      
    Chr. 13 ppm 100 Neurol.      
  Oral Int. 2 mg/kg/day 100 Hemato.      
                 
ACROLEIN Inh. Acute 0.003 ppm 100 Resp. Final 08/07 000107-02-8
    Int. 0.00004 ppm 300 Resp.      
  Oral Int. 0.004 mg/kg/day 100 Gastro.      
                 
ACRYLONITRILE Inh. Acute 0.1 ppm 10 Neurol. Final 12/90 000107-13-1
  Oral Acute 0.1 mg/kg/day 100 Develop.      
    Int. 0.01 mg/kg/day 1000 Repro.      
    Chr. 0.04 mg/kg/day 100 Hemato.      
                 
ALDRIN Oral Acute 0.002 mg/kg/day 1000 Develop. Final 09/02 000309-00-2
    Chr. 0.00003 mg/kg/day 1000 Hepatic      
                 
ALUMINUM Oral Int. 1.0 mg/kg/day 30 Neurol. Draft 09/06 007429-90-5
    Chr. 1.0 mg/kg/day 90 Neurol.      
                 
AMERICIUM Rad. Acute 4 mSv/yr 3 Develop. Final 10/04 007440-35-9
    Chr. 1 mSv/yr 3 Other      
                 
AMMONIA Inh. Acute 1.7 ppm 30 Resp. Final 10/04 007664-41-7
    Chr. 0.1 ppm 30 Resp.      
                 
ANTHRACENE Oral Int. 10 mg/kg/day 100 Hepatic Final 08/95 000120-12-7
                 
ARSENIC Oral Acute 0.005 mg/kg/day 10 Gastro. Draft 09/05 007440-38-2
    Chr. 0.0003 mg/kg/day 3 Dermal      
                 
ATRAZINE Oral Acute 0.01 mg/kg/day 100 Body Wt. Final 09/03 001912-24-9
    Int. 0.003 mg/kg/day 300 Repro.      
                 
BARIUM, SOLUBLE SALTS Oral Int. 0.2 mg/kg/day 300 Renal Final 08/07 007440-39-3
    Chr. 0.2 mg/kg/day 300 Renal      
                 
BENZENE Inh. Acute 0.009 ppm 300 Immuno. Final 08/07 000071-43-2
    Int. 0.006 ppm 300 Immuno.      
    Chr. 0.003 ppm 10 Immuno.      
  Oral Chr 0.0005 mg/kg/day 30 Immuno.      
                 
BERYLLIUM Oral Chr. 0.002 mg/kg/day 300 Gastro. Final 09/02 007440-41-7
                 
BIS(CHLOROMETHYL) ETHER Inh. Int. 0.0003 ppm 100 Resp. Final 12/89 000542-88-1
                 
BIS(2 CHLOROETHYL) ETHER Inh. Int. 0.02 ppm 1000 Body Wt. Final 12/89 000111-44-4
                 
BORON AND COMPOUNDS Inh. Acute 0.01 mg/m3 30 Resp. Draft 09/07 007440-42-8  
  Oral   Acute 0.2 mg/kg/day 100 Develop.        
    Int. 0.2 mg/kg/day 66 Develop.      
                 
BROMODICHLOROMETHANE Oral Acute 0.04 mg/kg/day 1000 Hepatic Final 12/89 000075-27-4
    Chr. 0.02 mg/kg/day 1000 Renal      
                 
BROMOFORM Oral Acute 0.7 mg/kg/day 100 Hepatic Final 09/05 000075-25-2
    Int. 0.2 mg/kg/day 300 Hepatic      
    Chr. 0.02 mg/kg/day 3000 Hepatic      
                 
BROMOMETHANE Inh. Acute 0.05 ppm 100 Neurol. Final 09/92 000074-83-9
    Int. 0.05 ppm 100 Neurol.      
    Chr. 0.005 ppm 100 Neurol.      
  Oral Int. 0.003 mg/kg/day 100 Gastro.      
                 
CADMIUM Oral Chr. 0.0002 mg/kg/day 10 Renal Final 07/99 007440-43-9
                 
CARBON DISULFIDE Inh. Chr. 0.3 ppm 30 Neurol. Final 08/96 000075-15-0
  Oral Acute 0.01 mg/kg/day 300 Hepatic      
                 
CARBON TETRACHLORIDE Inh. Int. 0.03 ppm 30 Hepatic Final 09/05 000056-23-5
    Chr. 0.03 ppm 30 Hepatic      
  Oral Acute 0.02 mg/kg/day 300 Hepatic      
    Int. 0.007 mg/kg/day 100 Hepatic      
                 
CESIUM Rad. Acute 4 mSv 3 Develop. Final 10/04 007440-46-2
    Chr. 1 mSv/yr 3 Other      
                 
CHLORDANE Inh. Int. 0.0002 mg/m3 100 Hepatic Final 05/94 000057-74-9
    Chr. 0.00002 mg/m3 1000 Hepatic      
  Oral Acute 0.001 mg/kg/day 1000 Develop.      
    Int. 0.0006 mg/kg/day 100 Hepatic      
    Chr. 0.0006 mg/kg/day 100 Hepatic      
                 
CHLORDECONE Oral Acute 0.01 mg/kg/day 100 Neurol. Final 08/95 000143-50-0
    Int. 0.0005 mg/kg/day 100 Renal      
    Chr. 0.0005 mg/kg/day 100 Renal      
                 
CHLORFENVINPHOS Oral Acute 0.002 mg/kg/day 1000 Neurol. Final 09/97 000470-90-6
    Int. 0.002 mg/kg/day 1000 Immuno.      
    Chr. 0.0007 mg/kg/day 1000 Neurol.      
                 
CHLORINE DIOXIDE Inh. Int. 0.001 ppm 300 Resp. Final 10/04 010049-04-4
                 
CHLORITE Oral Int. 0.1 mg/kg/day 30 Neurol. Final 10/04 007758-19-2
                 
CHLOROBENZENE Oral Int. 0.4 mg/kg/day 100 Hepatic Final 12/90 000108-90-7
                 
CHLORODIBROMOMETHANE Oral Acute 0.1 mg/kg/day 300 Hepatic Final 09/05 000124-48-1
    Chr. 0.09 mg/kg/day 300 Hepatic      
                 
CHLOROETHANE Inh. Acute 15 ppm 100 Develop. Final 12/98 000075-00-3
                 
CHLORINE Inh. Acute 0.07 ppm 3 Resp. Draft 09/07 007782-50-5
    Int. 0.002 ppm 90 Resp.      
    Chr. 0.00005 ppm 30 Resp.      
                 
CHLOROFORM Inh. Acute 0.1 ppm 30 Hepatic Final 09/97 000067-66-3
    Int. 0.05 ppm 300 Hepatic      
    Chr. 0.02 ppm 100 Hepatic      
  Oral Acute 0.3 mg/kg/day 100 Hepatic      
    Int. 0.1 mg/kg/day 100 Hepatic      
    Chr. 0.01 mg/kg/day 1000 Hepatic      
                 
CHLOROMETHANE Inh. Acute 0.5 ppm 100 Neurol. Final 12/98 000074-87-3
    Int. 0.2 ppm 300 Hepatic      
    Chr. 0.05 ppm 1000 Neurol.      
                 
CHLORPYRIFOS Oral Acute 0.003 mg/kg/day 10 Neurol. Final 09/97 002921-88-2
    Int. 0.003 mg/kg/day 10 Neurol.      
    Chr. 0.001 mg/kg/day 100 Neurol.      
                 
CHROMIUM(VI), AEROSOL MISTS Inh. Int. 0.000005 mg/m3 100 Resp. Final 09/00 007738-94-5
                 
CHROMIUM(VI), PARTICULATES Inh. Int. 0.001 mg/m3 30 Resp. Final 09/00 018540-29-9
                 
COBALT Inh. Chr. 0.0001 mg/m3 10 Resp. Final 10/04 007440-48-4
  Oral Int. 0.01 mg/kg/day 100 Hemato.      
  Rad. Acute 4 mSv 3 Develop.      
    Chr. 1 mSv/yr 3 Other      
                 
COPPER Oral Acute 0.01 mg/kg/day 3 Gastro. Final 10/04 007440-50-8
    Int. 0.01 mg/kg/day 3 Gastro.      
                 
CRESOLS Oral Int. 0.1 mg/kg/day 100 Resp. Draft 09/06 001319-77-3
                 
CYANIDE, SODIUM Oral Int. 0.05 mg/kg/day 100 Repro. Final 07/06 000143-33-9
                 
CYCLOTETRAMETHYLENE TETRANITRAMINE (HMX) Oral Acute 0.1 mg/kg/day 1000 Neurol. Final 09/97 002691-41-0
    Int. 0.05 mg/kg/day 1000 Hepatic      
                 
CYCLOTRIMETHYLENETRINITRAMINE (RDX) Oral Acute 0.06 mg/kg/day 100 Neurol. Final 06/95 000121-82-4
    Int. 0.03 mg/kg/day 300 Repro.      
                 
CYHALOTHRIN Oral Acute 0.01 mg/kg/day 100 Gastro. Final 09/03 068085-85-8
    Int. 0.01 mg/kg/day 100 Gastro.      
                 
CYPERMETHRIN Oral Acute 0.02 mg/kg/day 100 Neurol. Final 09/03 052315-07-8
                 
DDT, P,P'- Oral Acute 0.0005 mg/kg/day 1000 Develop. Final 09/02 000050-29-3
    Int. 0.0005 mg/kg/day 100 Hepatic      
                 
DI(2-ETHYLHEXYL)PHTHALATE Oral Int. 0.1 mg/kg/day 100 Repro. Final 09/02 000117-81-7
    Chr. 0.06 mg/kg/day 100 Repro.      
                 
DI-N-BUTYL PHTHALATE Oral Acute 0.5 mg/kg/day 100 Develop. Final 09/01 000084-74-2
                 
DI-N-OCTYL PHTHALATE Oral Acute 3 mg/kg/day 300 Hepatic Final 09/97 000117-84-0
    Int. 0.4 mg/kg/day 100 Hepatic      
                 
DIAZINON Inh. Int. 0.01 mg/m3 30 Neurol. Draft 09/06 000333-41-5
  Oral Acute 0.006 mg/kg/day 100 Neurol.      
    Int. 0.002 mg/kg/day 100 Neurol.      
    Chr. 0.0007 mg/kg/day 100 Neurol.      
                 
DICHLOROBENZENE, 1,2- Oral Acute 0.7 mg/kg/day 100 Hepatic Final 07/06 000095-50-1
    Int. 0.6 mg/kg/day 100 Hepatic      
    Chr. 0.3 mg/kg/day 100 Renal      
                 
DICHLOROBENZENE, 1,3- Oral Acute 0.4 mg/kg/day 100 Hepatic Final 07/06 000541-73-1
    Int. 0.02 mg/kg/day 100 Endocr.      
                 
DICHLOROBENZENE, 1,4- Inh. Acute 2 ppm 10 Ocular Final 07/06 000106-46-7
    Int. 0.2 ppm 100 Hepatic      
    Chr. 0.01 ppm 30 Resp.      
  Oral Int. 0.07 mg/kg/day 100 Hepatic      
    Chr. 0.07 mg/kg/day 100 Hepatic      
                 
DICHLORVOS Inh. Acute 0.002 ppm 100 Neurol. Final 09/97 000062-73-7
    Int. 0.0003 ppm 100 Neurol.      
    Chr. 0.00006 ppm 100 Neurol.      
  Oral Acute 0.004 mg/kg/day 1000 Neurol.      
    Int. 0.003 mg/kg/day 10 Neurol.      
    Chr. 0.0005 mg/kg/day 100 Neurol.      
                 
DIELDRIN Oral Int. 0.0001 mg/kg/day 100 Neurol. Final 09/02 000060-57-1
    Chr. 0.00005 mg/kg/day 100 Hepatic      
                 
DIETHYL PHTHALATE Oral Acute 7 mg/kg/day 300 Repro. Final 06/95 000084-66-2
    Int. 6 mg/kg/day 300 Hepatic      
                 
DIISOPROPYL METHYLPHOSPHONATE Oral Int. 0.8 mg/kg/day 100 Hemato. Final 10/98 001445-75-6
(DIMP)   Chr. 0.6 mg/kg/day 100 Hemato.      
                 
DIMETHYLARSINIC ACID (DMA) Oral Chr. 0.02 mg/kg/day 100 Renal Final 08/07 000075-60-5
                 
DISULFOTON Inh. Acute 0.006 mg/m3 30 Neurol. Final 08/95 000298-04-4
    Int. 0.0002 mg/m3 30 Neurol.      
  Oral Acute 0.001 mg/kg/day 100 Neurol.      
    Int. 0.00009 mg/kg/day 100 Develop.      
    Chr. 0.00006 mg/kg/day 1000 Neurol.      
                 
ENDOSULFAN Oral Int. 0.005 mg/kg/day 100 Immuno. Final 09/00 000115-29-7
    Chr. 0.002 mg/kg/day 100 Hepatic      
                 
ENDRIN Oral Int. 0.002 mg/kg/day 100 Neurol. Final 08/96 000072-20-8
    Chr. 0.0003 mg/kg/day 100 Neurol.      
                 
ETHION Oral Acute 0.002 mg/kg/day 30 Neurol. Final 09/00 000563-12-2
    Int. 0.002 mg/kg/day 30 Neurol.      
    Chr. 0.0004 mg/kg/day 150 Neurol.      
                 
ETHYLBENZENE Inh. Acute 10 ppm 30 Neurol. Draft 09/07 000100-41-4
    Int. 0.7 ppm 300 Neurol.      
    Chr. 0.3 ppm 300 Renal      
  Oral Int.   0.5 mg/kg/day 100 Hepatic      
                 
ETHYLENE GLYCOL Inh. Acute 2 mg/m3 10 Renal Draft 09/07 000107-21-1
  Oral Acute 0.8 mg/kg/day 100 Develop.      
    Int. 0.8 mg/kg/day 100 Develop      
                 
ETHYLENE OXIDE Inh. Int. 0.09 ppm 100 Renal Final 12/90 000075-21-8
                 
FLUORANTHENE Oral Int. 0.4 mg/kg/day 300 Hepatic Final 08/95 000206-44-0
                 
FLUORENE Oral Int. 0.4 mg/kg/day 300 Hepatic Final 08/95 000086-73-7
                 
FLUORIDE, SODIUM Oral Chr. 0.05 mg/kg/day 3 Musculo. Final 09/03 007681-49-4
                 
FLUORINE Inh. Acute 0.01 ppm 10 Resp. Final 09/03 007782-41-4
                 
FORMALDEHYDE Inh. Acute 0.04 ppm 9 Resp. Final 07/99 000050-00-0
    Int. 0.03 ppm 30 Resp.      
    Chr. 0.008 ppm 30 Resp.      
  Oral Int. 0.3 mg/kg/day 100 Gastro.      
    Chr. 0.2 mg/kg/day 100 Gastro.      
                 
FUEL OIL NO.2 Inh. Acute 0.02 mg/m3 1000 Neurol. Final 06/95 068476-30-2
                 
GUTHION Inh. Acute 0.02 mg/m3 30 Neurol. Draft 09/06 000086-50-0
    Int. 0.01 mg/m3 30 Neurol.      
    Chr. 0.01 mg/m3 30 Neurol.      
  Oral Acute 0.01 mg/kg/day 100 Neurol.      
    Int. 0.003 mg/kg/day 100 Neurol.      
    Chr. 0.003 mg/kg/day 100 Neurol.      
                 
HEPTACHLOR Oral Acute 0.0006 mg/kg/day 3000 Repro. Final 08/07 000076-44-8
    Int. 0.0001 mg/kg/day 300 Immuno. Draft 09/05  
                 
HEXACHLOROBENZENE Oral Acute 0.008 mg/kg/day 300 Develop. Final 09/02 000118-74-1
    Int. 0.0001 mg/kg/day 90 Repro.      
    Chr. 0.00005 mg/kg/day 300 Develop.      
                 
HEXACHLOROBUTADIENE Oral Int. 0.0002 mg/kg/day 1000 Renal Final 05/94 000087-68-3
                 
HEXACHLOROCYCLOHEXANE, ALPHA- Oral Chr. 0.008 mg/kg/day 100 Hepatic Final 09/05 000319-84-6
                 
HEXACHLOROCYCLOHEXANE, BETA- Oral Acute 0.05 mg/kg/day 100 Neurol. Final 09/05 000319-85-7
    Int. 0.0006 mg/kg/day 300 Hepatic      
                 
HEXACHLOROCYCLOHEXANE, GAMMA- Oral Acute 0.003 mg/kg/day 300 Develop. Final 09/05 000058-89-9
    Int. 0.00001 mg/kg/day 1000 Immuno.      
                 
HEXACHLOROCYCLOPENTADIENE Inh. Int. 0.01 ppm 30 Resp. Final 07/99 000077-47-4
    Chr. 0.0002 ppm 90 Resp.      
  Oral Int. 0.1 mg/kg/day 100 Renal      
                 
HEXACHLOROETHANE Inh. Acute 6 ppm 30 Neurol. Final 09/97 000067-72-1
    Int. 6 ppm 30 Neurol.      
  Oral Acute 1 mg/kg/day 100 Hepatic      
    Int. 0.01 mg/kg/day 100 Hepatic      
                 
HEXAMETHYLENE DIISOCYANATE Inh. Int. 0.00003 ppm 30 Resp. Final 10/98 000822-06-0
    Chr. 0.00001 ppm 90 Resp.      
                 
HEXANE, N- Inh. Chr. 0.6 ppm 100 Neurol. Final 07/99 000110-54-3
                 
HYDRAZINE Inh. Int. 0.004 ppm 300 Hepatic Final 09/97 000302-01-2
                 
HYDROGEN FLUORIDE Inh. Acute 0.02 ppm 30 Resp. Final 09/03 007664-39-3
                 
HYDROGEN SULFIDE Inh. Acute 0.07 ppm 27 Resp. Final 07/06 007783-06-4
    Int. 0.02 ppm 30 Resp.      
                 
IODIDE Oral Acute 0.01 mg/kg/day 1 Endocr. Final 10/04 007553-56-2
    Chr. 0.01 mg/kg/day 1 Endocr.      
                 
IONIZING RADIATION, N.O.S. Rad. Acute 4 mSv 3 Neurol. Final 09/99 HZ1800-45-T
    Chr. 1 mSv/yr 3 Other      
                 
ISOPHORONE Oral Int. 3 mg/kg/day 100 Other Final 12/89 000078-59-1
    Chr. 0.2 mg/kg/day 1000 Hepatic      
                 
JP-4 Inh. Int. 9 mg/m3 300 Hepatic Final 06/95 050815-00-4
                 
JP-5/JP-8 Inh. Int. 3 mg/m3 300 Hepatic Final 10/98 HZ0600-26-T
                 
JP-7 Inh. Chr. 0.3 mg/m3 300 Hepatic Final 06/95 HZ0600-22-T
                 
KEROSENE Inh. Int. 0.01 mg/m3 1000 Hepatic Final 06/95 008008-20-6
                 
MALATHION Inh. Acute 0.2 mg/m3 100 Neurol. Final 09/03 000121-75-5
    Int. 0.02 mg/m3 1000 Resp.      
  Oral Int. 0.02 mg/kg/day 10 Neurol.      
    Chr. 0.02 mg/kg/day 100 Neurol.      
                 
MANGANESE Inh. Chr. 0.00004 mg/m3 500 Neurol. Final 09/00 007439-96-5
                 
MERCURIC CHLORIDE Oral Acute 0.007 mg/kg/day 100 Renal Final 03/99 007487-94-7
    Int. 0.002 mg/kg/day 100 Renal      
                 
MERCURY Inh. Chr. 0.0002 mg/m3 30 Neurol. Final 03/99 007439-97-6
                 
METHOXYCHLOR Oral Int. 0.005 mg/kg/day 1000 Repro. Draft 09/00 000072-43-5
                 
METHYL PARATHION Oral Int. 0.0007 mg/kg/day 300 Neurol. Final 09/01 000298-00-0
    Chr. 0.0003 mg/kg/day 100 Hemato.      
                 
METHYL-T-BUTYL ETHER Inh. Acute 2 ppm 100 Neurol. Final 08/96 001634-04-4
    Int. 0.7 ppm 100 Neurol.      
    Chr. 0.7 ppm 100 Renal      
  Oral Acute 0.4 mg/kg/day 100 Neurol.      
    Int. 0.3 mg/kg/day 300 Hepatic      
                 
METHYLENE CHLORIDE Inh. Acute 0.6 ppm 100 Neurol. Final 09/00 000075-09-2
    Int. 0.3 ppm 90 Hepatic      
    Chr. 0.3 ppm 30 Hepatic      
  Oral Acute 0.2 mg/kg/day 100 Neurol.      
    Chr. 0.06 mg/kg/day 100 Hepatic      
                 
METHYLMERCURY Oral Chr. 0.0003 mg/kg/day 4 Develop. Final 03/99 022967-92-6
                 
MIREX Oral Chr. 0.0008 mg/kg/day 100 Hepatic Final 08/95 002385-85-5
                 
MONOMETHYLARSONIC ACID (MMA) Oral Int. 0.1 mg/kg/day 100 Gastro. Final 08/07 000124-58-3
    Chr. 0.01 mg/kg/day 100 Renal      
                 
N-NITROSODI-N-PROPYLAMINE Oral Acute 0.095 mg/kg/day 100 Hepatic Final 12/89 000621-64-7
                 
NAPHTHALENE Inh. Chr. 0.0007 ppm 300 Resp. Final 09/05 000091-20-3
                 
  Oral Acute 0.6 mg/kg/day 90 Neurol.      
    Int. 0.6 mg/kg/day 90 Neurol.      
                 
NICKEL Inh. Int. 0.0002 mg/m3 30 Resp. Final 09/05 007440-02-0
    Chr. 0.00009 mg/m3 30 Resp.      
                 
PENTACHLOROPHENOL Oral Acute 0.005 mg/kg/day 1000 Develop. Final 09/01 000087-86-5
    Int. 0.001 mg/kg/day 1000 Repro.      
    Chr. 0.001 mg/kg/day 1000 Endocr.      
                 
PERCHLORATES Oral Chr. 0.0007 mg/kg/day 10 Endocr. Draft 09/05 007778-74-7
                 
PERMETHRIN Oral Acute 0.3 mg/kg/day 100 Neurol. Final 09/03 052645-53-1
    Int. 0.2 mg/kg/day 100 Neurol.      
                 
PHENOL Inh. Acute 0.02 ppm 30 Resp. Draft 09/06 000108-95-2
  Oral Acute 0.6 mg/kg/day 100 Body Wt.      
                 
PHOSPHORUS, WHITE Inh. Acute 0.02 mg/m3 30 Resp. Final 09/97 007723-14-0
  Oral Int. 0.0002 mg/kg/day 100 Repro.      
                 
POLYBROMINATED BIPHENYLS (PBBs) Oral Acute 0.01 mg/kg/day 100 Endocr. Final 10/04 036355-01-8
                 
POLYBROMINATED DIPHENYL ETHERS (PBDEs), LOWER BROMINATED Inh Int. 0.006 mg/m3 90 Endocr. Final 10/04 032534-81-9
  Oral Acute 0.03 mg/kg/day 30 Endocr.     032536-52-0
    Int. 0.007 mg/kg/day 300 Hepatic      
                 
PBDE, DECABROMINATED Oral Int. 10 mg/kg/day 100 Develop. Final 10/04 001163-19-5
                 
POLYCHLORINATED BIPHENYLS (PCBs) (Aroclor 1254) Oral Int. 0.03 ug/kg/day 300 Neurol. Final 11/00 011097-69-1
    Chr. 0.02 ug/kg/day 300 Immuno.      
                 
PROPYLENE GLYCOL DINITRATE Inh. Acute 0.003 ppm 10 Neurol. Final 06/95 006423-43-4
    Int. 0.00004 ppm 1000 Hemato.      
    Chr. 0.00004 ppm 1000 Hemato.      
                 
PROPYLENE GLYCOL Inh. Int. 0.009 ppm 1000 Resp. Final 09/97 000057-55-6
                 
REFRACTORY CERAMIC FIBERS Inh. Chr. 0.03 fibers/cc 30 Resp. Final 10/04 HZ0900-26-T
                 
SELENIUM Oral Chr. 0.005 mg/kg/day 3 Dermal Final 09/03 007782-49-2
                 
STRONTIUM Oral Int. 2 mg/kg/day 30 Musculo. Final 10/04 007440-24-6
                 
STYRENE Inh. Acute 2 ppm 10 Neurol. Draft 09/07 000100-42-5
    Chr. 0.2 ppm 100 Neurol.        
  Oral Acute 0.1 mg/kg/day 1000 Neurol.      
                 
SULFUR DIOXIDE Inh. Acute 0.01 ppm 9 Resp. Final 12/98 007446-09-5
                 
SULFUR MUSTARD Inh. Acute 0.0007 mg/m3 30 Ocular Final 09/03 000505-60-2
    Int. 0.00002 mg/m3 30 Ocular      
  Oral Acute 0.5 µg/kg/day 1000 Develop.      
    Int. 0.07 µg/kg/day 300 Gastro.      
                 
TETRACHLOROETHYLENE Inh. Acute 0.2 ppm 10 Neurol. Final 09/97 000127-18-4
    Chr. 0.04 ppm 100 Neurol.      
  Oral Acute 0.05 mg/kg/day 100 Develop.      
                 
TIN, INORGANIC Oral Int. 0.3 mg/kg/day 100 Hemato. Final 09/05 007440-31-5
                 
TIN, DIBUTYL- Oral Int. 0.005 mg/kg/day 1000 Immunol. Final 09/05 000683-18-1
                 
TIN, TRIBUTYL- Oral Int. 0.0003 mg/kg/day 100 Immunol. Final 09/05 000056-36-9
    Chr. 0.0003 mg/kg/day 100 Immunol.      
                 
TITANIUM TETRACHLORIDE Inh. Int. 0.01 mg/m3 90 Resp. Final 09/97 007550-45-0
    Chr. 0.0001 mg/m3 90 Resp.      
                 
TOLUENE Inh. Acute 1 ppm 10 Neurol. Final 09/00 000108-88-3
    Chr. 0.08 ppm 100 Neurol.      
  Oral Acute 0.8 mg/kg/day 300 Neurol.      
    Int. 0.02 mg/kg/day 300 Neurol.      
                 
TOXAPHENE Oral Acute 0.005 mg/kg/day 1000 Hepatic Final 08/96 008001-35-2
    Int. 0.001 mg/kg/day 300 Hepatic      
                 
TRICHLOROETHYLENE Inh. Acute 2 ppm 30 Neurol. Final 09/97 000079-01-6
    Int. 0.1 ppm 300 Neurol.      
  Oral Acute 0.2 mg/kg/day 300 Develop.      
                 
URANIUM, HIGHLY SOLUBLE SALTS Inh. Int. 0.0004 mg/m3 90 Renal Final 09/99 HZ1800-90-T
    Chr. 0.0003 mg/m3 30 Renal      
  Oral Int. 0.002 mg/kg/day 30 Renal      
                 
URANIUM, INSOLUBLE COMPOUNDS Inh. Int. 0.008 mg/m3 30 Renal Final 09/99 HZ1800-92-T
                 
VANADIUM Inh. Acute 0.0002 mg/m3 100 Resp. Final 07/92 007440-62-2
  Oral Int. 0.003 mg/kg/day 100 Renal      
                 
VINYL ACETATE Inh. Int. 0.01 ppm 100 Resp. Final 07/92 000108-05-4
                 
VINYL CHLORIDE Inh. Acute 0.5 ppm 30 Develop. Final 07/06 000075-01-4
    Int. 0.03 ppm 30 Hepatic      
  Oral Chr. 0.003 mg/kg/day 30 Hepatic      
                 
XYLENES, MIXED Inh. Acute 2 ppm 30 Neurol. Final 08/07 001330-20-7
    Int. 0.6 ppm 90 Neurol.      
    Chr. 0.05 ppm 300 Neurol.      
  Oral Acute 1 mg/kg/day 100 Neurol.      
    Int. 0.4 mg/kg/day 1000 Neurol.      
    Chr. 0.2 mg/kg/day 1000 Neurol.      
                 
ZINC Oral Int. 0.3 mg/kg/day 3 Hemato. Final 09/05 007440-66-6
    Chr. 0.3 mg/kg/day 3 Hemato.      
                 
1-METHYLNAPHTHALENE Oral Chr. 0.07 mg/kg/day 1000 Resp. Final 09/05 000090-12-0
                 
2-METHYLNAPHTHALENE Oral Chr. 0.04 mg/kg/day 100 Resp. Final 09/05 000091-57-6
                 
1,1-DICHLOROETHENE Inh. Int. 0.02 ppm 100 Hepatic Final 05/94 000075-35-4
  Oral Chr. 0.009 mg/kg/day 1000 Hepatic      
                 
1,1-DIMETHYLHYDRAZINE Inh. Int. 0.0002 ppm 300 Hepatic Final 09/97 000057-14-7
                 
1,1,1-TRICHLOROETHANE Inh. Acute 2 ppm 100 Neurol. Final 07/06 000071-55-6
    Int. 0.7 ppm 100 Neurol.      
  Oral Int. 20 mg/kg/day 100 Body Wt.      
                 
1,1,2-TRICHLOROETHANE Oral Acute 0.3 mg/kg/day 100 Neurol. Final 12/89 000079-00-5
    Int. 0.04 mg/kg/day 100 Hepatic      
                 
1,1,2,2-TETRACHLOROETHANE Oral Int. 0.5 mg/kg/day 100 Hepatic Draft 09/06 000079-34-5
                 
1,2-DIBROMO-3-CHLOROPROPANE Inh. Int. 0.0002 ppm 100 Repro. Final 09/92 000096-12-8
  Oral Int. 0.002 mg/kg/day 1000 Repro.      
                 
1,2-DICHLOROETHANE Inh. Chr. 0.6 ppm 90 Hepatic Final 09/01 000107-06-2
  Oral Int. 0.2 mg/kg/day 300 Renal      
                 
1,2-DICHLOROETHENE, CIS- Oral Acute 1 mg/kg/day 100 Hemato. Final 08/96 000156-59-2
    Int. 0.3 mg/kg/day 100 Hemato.      
                 
1,2-DICHLOROETHENE, TRANS- Inh. Acute 0.2 ppm 1000 Hepatic Final 08/96 000156-60-5
    Int. 0.2 ppm 1000 Hepatic      
  Oral Int. 0.2 mg/kg/day 100 Hepatic      
                 
1,2-DICHLOROPROPANE Inh. Acute 0.05 ppm 1000 Resp. Final 12/89 000078-87-5
    Int. 0.007 ppm 1000 Resp.      
  Oral Acute 0.1 mg/kg/day 1000 Neurol.      
    Int. 0.07 mg/kg/day 1000 Hemato.      
    Chr. 0.09 mg/kg/day 1000 Hepatic      
                 
1,2-DIMETHYLHYDRAZINE Oral Int. 0.0008 mg/kg/day 1000 Hepatic Final 09/97 000540-73-8
                 
1,2,3-TRICHLOROPROPANE Inh. Acute 0.0003 ppm 100 Resp. Final 09/92 000096-18-4
  Oral Int. 0.06 mg/kg/day 100 Hepatic      
                 
1,3-DICHLOROPROPENE Inh. Int. 0.008 ppm 30 Resp. Draft 09/06 000542-75-6
    Chr. 0.007 ppm 30 Resp.      
  Oral Int. 0.04 mg/kg/day 100 Gastro.      
    Chr. 0.03 mg/kg/day 100 Gastro.      
                 
1,3-DINITROBENZENE Oral Acute 0.008 mg/kg/day 100 Repro. Final 06/95 000099-65-0
    Int. 0.0005 mg/kg/day 1000 Hemato.      
                 
1,4-DIOXANE Inh. Acute 2 ppm 10 Ocular Final 07/06 000123-91-1
    Int. 1 ppm 30 Hepatic      
    Chr. 1 ppm 30 Hepatic      
  Oral Acute 4 mg/kg/day 100 Resp.      
    Int. 0.6 mg/kg/day 100 Hepatic      
    Chr. 0.1 mg/kg/day 100 Hepatic      
                 
2-BUTOXYETHANOL Inh. Acute 6 ppm 9 Hemato. Final 10/98 000111-76-2
    Int. 3 ppm 9 Hemato.      
    Chr. 0.2 ppm 3 Hemato.      
  Oral Acute 0.4 mg/kg/day 90 Hemato.      
    Int. 0.07 mg/kg/day 1000 Hepatic      
                 
2,3-DICHLOROPROPENE Inh. Acute 0.002 ppm 90 Resp. Draft 09/06 000078-88-6
                 
2,3,4,7,8-PENTACHLORO­DIBENZOFURAN Oral Acute 0.001 ug/kg/day 3000 Immuno. Final 05/94 057117-31-4
    Int. 0.00003 ug/kg/day 3000 Hepatic      
                 
2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN Oral Acute 0.0002 ug/kg/day 21 Immuno. Final 12/98 001746-01-6
    Int. 0.00002 ug/kg/day 30 Lymphor.      
    Chr. 0.000001 ug/kg/day 90 Develop.      
                 
2,4-DICHLOROPHENOL Oral Int. 0.003 mg/kg/day 100 Immuno. Final 07/99 000120-83-2
                 
2,4-DINITROPHENOL Oral Acute 0.01 mg/kg/day 100 Body Wt. Final 08/95 000051-28-5
                 
2,4-DINITROTOLUENE Oral Acute 0.05 mg/kg/day 100 Neurol. Final 12/98 000121-14-2
    Chr. 0.002 mg/kg/day 100 Hemato.      
                 
2,4,6-TRINITROTOLUENE Oral Int. 0.0005 mg/kg/day 1000 Hepatic Final 06/95 000118-96-7
                 
2,6-DINITROTOLUENE Oral Int. 0.004 mg/kg/day 1000 Hemato. Final 12/98 000606-20-2
                 
4-CHLOROPHENOL Oral Acute 0.01 mg/kg/day 100 Hepatic Final 07/99 000106-48-9
                 
4,4'-METHYLENEBIS(2-CHLOROANILINE) Oral Chr. 0.003 mg/kg/day 3000 Hepatic Final 05/94 000101-14-4
                 
4,4'-METHYLENEDIANILINE Oral Acute 0.2 mg/kg/day 300 Hepatic Final 10/98 000101-77-9
    Int. 0.08 mg/kg/day 100 Hepatic      
                 
4,6-DINITRO-O-CRESOL Oral Acute 0.004 mg/kg/day 100 Neurol. Final 08/95 000534-52-1
    Int. 0.004 mg/kg/day 100 Neurol.      

This page was updated on 08/20/2008