Out of 30 ZIP codes with data in South Carolina, these are the lowest-ranked areas for radon zone. See also: National ZIP Codes with Highest Radon Risk | All South Carolina Rankings
| Statistic | Value |
|---|---|
| ZIP codes ranked | 30 |
| Lowest value | Zone 1 (High) |
| Median value | Zone 1 (High) |
| State | South Carolina |
30 Lowest-Ranked ZIP Codes
| Rank | ZIP Code | City | State | Radon Zone | Safety Score |
|---|---|---|---|---|---|
| 1 | 29636 | Conestee | SC | Zone 1 (High) | 40/100 |
| 2 | 29662 | Mauldin | SC | Zone 1 (High) | 40/100 |
| 3 | 29683 | Slater | SC | Zone 1 (High) | 40/100 |
| 4 | 29687 | Taylors | SC | Zone 1 (High) | 45/100 |
| 5 | 29615 | Greenville | SC | Zone 1 (High) | 47/100 |
| 6 | 29607 | Greenville | SC | Zone 1 (High) | 52/100 |
| 7 | 29617 | Greenville | SC | Zone 1 (High) | 52/100 |
| 8 | 29322 | Campobello | SC | Zone 1 (High) | 53/100 |
| 9 | 29635 | Cleveland | SC | Zone 1 (High) | 53/100 |
| 10 | 29644 | Fountain Inn | SC | Zone 1 (High) | 53/100 |
| 11 | 29610 | Greenville | SC | Zone 1 (High) | 55/100 |
| 12 | 29612 | Greenville | SC | Zone 1 (High) | 55/100 |
| 13 | 29613 | Greenville | SC | Zone 1 (High) | 55/100 |
| 14 | 29614 | Greenville | SC | Zone 1 (High) | 55/100 |
| 15 | 29616 | Greenville | SC | Zone 1 (High) | 55/100 |
| 16 | 29661 | Marietta | SC | Zone 1 (High) | 56/100 |
| 17 | 29601 | Greenville | SC | Zone 1 (High) | 57/100 |
| 18 | 29605 | Greenville | SC | Zone 1 (High) | 57/100 |
| 19 | 29609 | Greenville | SC | Zone 1 (High) | 57/100 |
| 20 | 29611 | Greenville | SC | Zone 1 (High) | 57/100 |
| 21 | 29681 | Simpsonville | SC | Zone 1 (High) | 60/100 |
| 22 | 29603 | Greenville | SC | Zone 1 (High) | 62/100 |
| 23 | 29606 | Greenville | SC | Zone 1 (High) | 62/100 |
| 24 | 29608 | Greenville | SC | Zone 1 (High) | 62/100 |
| 25 | 29650 | Greer | SC | Zone 1 (High) | 65/100 |
| 26 | 29651 | Greer | SC | Zone 1 (High) | 65/100 |
| 27 | 29680 | Simpsonville | SC | Zone 1 (High) | 65/100 |
| 28 | 29690 | Travelers Rest | SC | Zone 1 (High) | 65/100 |
| 29 | 29652 | Greer | SC | Zone 1 (High) | 66/100 |
| 30 | 29356 | Landrum | SC | Zone 1 (High) | 70/100 |
Methodology
Radon rankings are based on EPA county-level radon zone classifications. Zone 1 (highest risk) has predicted average indoor radon levels above 4 pCi/L — the EPA action level. Zone 2 is moderate (2-4 pCi/L) and Zone 3 is low (below 2 pCi/L). Within Zone 1, ZIP codes are sub-ranked by Home Safety Score to prioritize areas with compounding risk factors.
Data sources: EPA Safe Drinking Water Information System (SDWIS), FEMA National Flood Insurance Program, EPA radon zone maps, EIA electricity rates, and Consumer Confidence Reports. Last updated: 2026-06-04.
Frequently Asked Questions
What is EPA Radon Zone 1?
Zone 1 is the EPA highest-risk classification, meaning the county has predicted average indoor radon levels above 4 pCi/L — the level at which the EPA recommends mitigation. Radon causes about 21,000 lung cancer deaths per year in the U.S.
Should I test for radon?
The EPA recommends testing all homes regardless of radon zone. A DIY test kit costs $15-40. Professional testing costs $150-250. If levels exceed 4 pCi/L, mitigation systems ($800-2,500) can reduce radon by up to 99%.
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