Table 1.
(a and b) Overview of validation outcome
| Chemical | CAS No | Cat | Phase | Lab A | Lab B | Lab C | Lab D | Lab E | |
|---|---|---|---|---|---|---|---|---|---|
| (a) | |||||||||
| Chemicals with an expected positive outcome | |||||||||
| 1 | 2-AAF | 53-96-3 | TP | 2 | Pos | ||||
| 2 | IQ | 76180-96-6 | TP | 2 | Neg | ||||
| 3 | AZT | 30516-87-1 | TP | 2 | Pos | ||||
| 4 | BaP | 50-32-8 | TP | 2 | Pos | ||||
| 5 | 4-Chloroaniline | 106-47-8 | TP | 2 | Neg | ||||
| 6 | Cadmium chloride | 10108-64-2 | TP | 1 | Pos | Pos | Neg | ||
| 7 | CPPE | 27208-37-3 | TP | 2 | Pos | ||||
| 8 | CP | 6055-19-2 | TP | 2 | Pos | ||||
| 9 | 2,4-DAT | 95-80-7 | TP | 2 | Neg | ||||
| 10 | DMBA | 57-97-6 | TP | 1 | Pos | Pos | Pos | ||
| 11 | EMS | 62-50-0 | TP | 2 | Pos | ||||
| 12 | ENU | 759-73-9 | TP | 1 | Pos | Pos | Pos | ||
| 13 | Etoposide | 33419-42-0 | TP | 2 | Pos | ||||
| 14 | MNNG | 70-25-7 | TP | 2 | Pos | ||||
| 15 | Mitomycin C | 50-07-7 | TP | 1 | Pos | Equiv | Pos. | ||
| Chemicals with an expected negative outcome | |||||||||
| 16 | Amitrole | 61-82-5 | TN | 2 | Neg | ||||
| 17 | Ampicillin sodium salt | 69-52-3 | TN | 2 | Neg | ||||
| 18 | N-butyl chloride | 109-69-3 | TN | 2 | Neg | ||||
| 19 | Curcumin | 458-37-7 | MP | 2 | Neg | ||||
| 20 | Cyclohexanone | 108-94-1 | TN | 1 | Neg | Neg | Neg | ||
| 21 | 2,6-DAT | 823-40-5 | MP | 2 | Neg | ||||
| 22 | N,N-dicyclohexyl thiourea | 1212-29-9 | TN | 2 | Neg | ||||
| 23 | Ethionamide | 536-33-4 | MP | 2 | Equiv | ||||
| 24 | DEHP | 117-81-7 | TN | 1 | Neg | Neg | Neg | ||
| 25 | Eugenol | 97-53-0 | MP | 1 | Neg | Neg | Neg | ||
| 26 | Glyoxal | 107-22-2 | MP | 2 | Neg | ||||
| 27 | d-Mannitol | 69-65-8 | TN | 2 | Neg | ||||
| 28 | 4-Nitrophenol | 100-02-7 | MP | 2 | Neg | ||||
| 29 | Propyl gallate | 121-79-9 | MP | 1 | Neg | Neg | Neg | ||
| 30 | Resorcinol | 108-46-3 | MP | 2 | Pos | ||||
| 31 | Sodium xylene sulfonate | 1300-72-7 | MP | 2 | Neg | ||||
| 32 | TBHQ | 1948-33-0 | MP | 2 | Equiv | ||||
| (b) | |||||||||
| Chemicals with an expected positive outcome | |||||||||
| 15 | Mitomycin C | 50-07-7 | TP | 1 | Pos | . | |||
| Chemicals with an expected negative outcome | |||||||||
| 23 | Ethionamide | 536-33-4 | MP | 2 | Neg | ||||
| 30 | Resorcinol | 108-46-3 | MP | 2 | Equiv | ||||
| 32 | TBHQ | 1948-33-0 | MP | 2 | Neg |
In Phase 1, each chemical was tested in three laboratories (14). Subsequently, in Phase 2, chemicals were each tested in one laboratory only to expand the chemical space tested in the RS comet assay or to expand the overlap with chemicals tested in the RSMN. Cat – Category, i.e., expected outcome based on historical in vitro and in vivo genotoxicity or carcinogenicity data as provided in supplementary Table 1, available at Mutagenesis Online; MP = misleading positive; TN = true negative; TP = true positive; Pos = positive study outcome, DNA damage detected; Neg = negative; Equiv = equivocal. (a) Outcome as per expert judgement of the performing laboratory before decoding; (b) discordant calls as per application of the (later established) evaluation criteria agreed by the Steering Committee and other external experts