National Toxicology Program

PCB mixture of 3,3',4,4',5 Pentachlorobiphenyl (PCB 126) and 2,3',4,4',5 Pentachlorobiphenyl (PCB 118) (TR-531)

The Subcommittee accepted unanimously (9 yes, 0 no) the conclusions as written, clear evidence of carcinogenic activity of the mixture of PCB 126 and PCB 118 in female Harlan Sprague-Dawley rats.

2,2',4,4',5,5'-Hexachloro-biphenyl (PCB 153) (TR-529)

The Subcommittee accepted unanimously (9 yes, 0 no) the conclusions as written, equivocal evidence of carcinogenic activity of PCB 153 in female Harlan Sprague- Dawley rats. of 3,3',4,4',5-pentachlorobiphenyl in female rats.

PCB mixture (PCB 126 / PCB153) (TR-530)

The Subcommittee accepted unanimously (9 yes, 0 no) the conclusions as written, clear evidence of carcinogenic activity of a constant ratio binary mixture of PCB 126 and PCB 153 in female Harlan Sprague-Dawley rats.

3'-Azido-3'thymidine (TR-522)

The Subcommittee accepted unanimously (7 yes, 0 no, 2 abstentions) the conclusions, clear evidence of carcinogenic activity in F1 male mice exposed transplacentally to AZT and no evidence of carcinogenic activity in F1 female mice exposed transplacentally to 50, 100, 200, or 300 mg/kg.

Sodium chlorate (TR-517)

The Subcommittee accepted (9 yes, 0 no) the conclusions as written, some evidence of carcinogenic activity of sodium chlorate in male and female F344/N rats, no evidence of carcinogenic activity in male B6C3F₁ mice, and equivocal evidence of carcinogenic activity in female B6C3F₁ mice.

Bromodichloromethane (TR-532)

The Subcommittee accepted (9 yes, 0 no) the conclusions as written, no evidence of carcinogenic activity of bromodichloromethane in male F344/N rats and in female B6C3F₁ mice exposed to target concentrations of 175, 350, or 700 mg/L.

Benzophenone (TR-533)

The Subcommittee accepted (9 yes, 0 no) the conclusions as written, some evidence of carcinogenic activity of benzophenone in male F344/N rats, equivocal evidence of carcinogenic activity in female F344/N rats, and some evidence of carcinogenic activity in male and female B6C3F₁ mice.

Anthraquinone reviewed at the February 17-18, 2004 meeting (TR-494)

At the February 17-18, 2004 meeting, the Subcommittee recommended that the title of the report be changed to "Anthracene-derived Anthraquinone" and that it be made clear throughout the report that the material used in the study was "anthracene-derived anthraquinone." (http://ntp.niehs.nih.gov/ntpweb/index.cfm?objectid=9404F3B3-F1F6-975E-70F0DB8B0FDF8F86). The NTP Board of Scientific Counselors at its June 29, 2004 meeting recommended that the title of this Draft NTP Technical Report be readdressed and the issue of contaminants in NTP study materials be discussed in greater detail (http://ntp.niehs.nih.gov/index.cfm?objectid=E0C45907-F1F6-975E-7E22FE18F93DFBA9).

The Subcommittee recommended (7 yes, 2 no) that reference to the test material as "anthracene-derived" anthraquinone be deleted from the title. The Subcommittee recommended (7 yes, 1 no, 1 abstention) that the sentence: "The term anthraquinone used in this report refers to anthracene-derived anthraquinone" be deleted from the conclusions. The Subcommittee asked the NTP to clearly identify in the report the purity of the material studied and include information on the additional follow-up studies of that material.