| Red stain in a lab | 18 |
| Red lab dye | 11 |
| Lab stain | 9 |
| Gasoline colorant | 17 |
| Dye whose name derives from the Greek word for "dawn" | 63 |
| Dye used as a toner | 19 |
| Dye chemical | 12 |
| Cousin of indigo | 16 |
| Coal-tar dye | 12 |
| Coal tar | 8 |
| Certain red dye | 15 |
| Biological stain | 16 |
| Red dye (Var.) | 14 |
| Red fluorescent dye: Var. | 25 |
| Dye used in making red ink (Var.) | 33 |
| Cosmetics dye: Var. | 19 |
| Emission-regulating org. | 24 |
| Clean Air Act org. | 18 |
| Clean air org. | 14 |
| Clean-air org. | 14 |
| UV index monitor | 16 |
| D.C. group | 10 |
| Air-quality org. | 16 |
| Govt. clean air watchdog | 24 |
| Ecol. watchdog | 14 |
| Eco-friendly org. | 17 |
| Fed. air quality monitor | 24 |
| Clean Water Act org. | 20 |
| MPG rater | 9 |
| Green org. | 10 |
| DDT banner | 10 |
| AQI monitor | 11 |
| Watchdog org. | 13 |
| Govt. watchdog | 14 |
| Environmental org. | 18 |
| Ecology agcy. | 13 |
| Air quality org. | 16 |
| Fed. watchdog | 13 |
| Antipollution org. | 18 |
| Superfund org. | 14 |
| MPG monitor | 11 |
| Clean air agcy. | 15 |
| Anti-pollution org. | 19 |
| Agcy. that polices polluters | 28 |
| Waste watchers: Abbr. | 21 |
| Org. established by Nixon | 25 |
| MPG raters | 10 |
| Green gp. | 9 |
| Fed. smog watchdog | 18 |
| Emissions detecting agcy. | 25 |
| Eco-friendly feds | 17 |
| Conservation org. | 17 |
| Air quality overseer (Abbr.) | 28 |
| Smog watchers: abbr. | 20 |
| Pollution-policing org. | 23 |
| Pollution-fighting org. | 23 |
| Pollution control org. | 22 |
| Org. with an Office of Water | 28 |
| Org. concerned with climate change | 34 |
| MPG-rating org. | 15 |
| MPG rating group | 16 |
| Mileage rating org. | 19 |
| Kind of rating | 14 |
| Fuel economy org. | 17 |
| Energy Star program org. | 24 |
| D.C. ecology group | 18 |
| 1972 DDT banner | 15 |
| Watchdog feds | 13 |
| Waste watchers gp. | 18 |
| Superfund enforcer: Abbr. | 25 |
| Superfund administrator (abbr.) | 31 |
| Pollution-control gp. | 21 |
| Org. that banned DDT | 20 |
| MPG org. | 8 |
| MPG determiner | 14 |
| Govt. emissions watchdog | 24 |
| Govt. air checker | 17 |
| Fed. ecology group | 18 |
| Ecological org. | 15 |
| Ecol. org. | 10 |
| Cleanup org. | 12 |
| Clean-air agcy. | 15 |
| Clean air grp. | 14 |
| Air-testing org. | 16 |
| Air-quality agcy. | 17 |
| Agcy. involved with cleanup | 27 |
| WasteWise watchdog (abbr.) | 26 |
| Waste watchers (abbr.) | 22 |
| U.S. emissions controller | 25 |
| Toxic-level monitor, briefly | 28 |
| They want to clear the air, briefly | 35 |
| Superfund administrator: Abbr. | 30 |
| Superfund administrator, briefly | 32 |
| Standards issuer, briefly | 25 |
| Smog watchdogs (Abbr.) | 22 |
| Smog watchdog: abbr. | 20 |
| Pollution watchdog: Abbr. | 25 |
| Pollution stds. setter | 22 |
| Pollution monitoring org. | 25 |
| Pesticide-regulating org. | 25 |