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Top 20 Hazardous Substances

From the CERCLA Priority List of Hazardous Substances for 2005

What is the Top 20 List?

The list below contains the Top 20 hazardous substances on the CERCLA Priority List of Hazardous Substances for 2005. The complete list of 275 substances is obtained from an annual evaluation fulfilling the conditions of CERCLA section 104 (i), as amended, which requires ATSDR and EPA to revise the Priority List of  Hazardous Substances periodically to include additional hazardous substances.

Further information about the evaluation process and the complete set of 275 substances on the current list can be accessed online at:

CERCLA Priority List of Hazardous Substances for 2005.

Each of the Top 20 substances listed below is identified with their 2005  Rank Number and includes a link to an ATSDR publication, the ToxFAQsTM  Sheet, which has further health and chemical information about that substance.

The ATSDR Division of Toxicology has prepared several sets of publications that provide answers to many health concerns that are voiced by community groups and give general information on various properties of each of these substances. Those publications are listed and may be accessed online at:

Top 20 Hazardous Substances from the 2005 CERCLA Priority List of Hazardous Substances

1 ARSENIC
2 LEAD
3 MERCURY
4 VINYL CHLORIDE
5 POLYCHLORINATED BIPHENYLS
6 BENZENE
7 POLYCYCLIC AROMATIC HYDROCARBONS
8 CADMIUM
9 BENZO(A)PYRENE
10 BENZO(B)FLUORANTHENE
11 CHLOROFORM
12 DDT, P,P'-
13 AROCLOR 1254
14 AROCLOR 1260
15 DIBENZO(A,H)ANTHRACENE
16 TRICHLOROETHYLENE
17 DIELDRIN
18 CHROMIUM, HEXAVALENT
19 PHOSPHORUS, WHITE
20 DDE, P,P'-

Where can I get more information?

Agency for Toxic Substances and Disease Registry
Division of Toxicology and Environmental Medicine
1600 Clifton Road NE, Mailstop F-32
Atlanta, GA 30333
Phone: 1- 800-232-4636 / TTY: 888-232-6348  
FAX: 770-488-4178
Email: cdcinfo@cdc.gov
This page was updated on 09/11/2007