For children and pregnant people, no level of lead is considered safe. Asbestos also has no safe threshold at any level. For these, treat any detection as a reason to consult a professional.
| Contaminant | Limit (ppm / mg/kg) | Source |
|---|---|---|
| Lead (Pb) | 80 (CA DTSC), 200 (EPA) | CA DTSC, EPA |
| Arsenic (As) | 0.67 | EPA RSL |
| Mercury (Hg) | 0.71 | DTSC (inorganic mercury) RSL |
| Copper (Cu) | 3100 | EPA RSL |
| Chromium (Cr VI) | 0.3 | EPA RSL |
| Zinc (Zn) | 23,300 | EPA RSL |
| Silver (Ag) | 390 | EPA RSL |
| Barium (Ba) | 15,000 | EPA RSL |
| Beryllium (Be) | 160 | EPA RSL |
| Cadmium (Cd) | 7.1 | EPA RSL |
| Cobalt (Co) | 23 | EPA RSL |
| Molybdenum (Mo) | 390 | EPA RSL |
| Nickel (Ni) | 140.88 | EPA RSL |
| Antimony (Sb) | 31 | EPA RSL |
| Selenium (Se) | 390 | EPA RSL |
| Thallium (Tl) | 0.78 | EPA RSL |
| Vanadium (V) | 39.3 | EPA RSL |
| Contaminant | Limit (ppm) | Source |
|---|---|---|
| Benzene | 1200 | EPA RSL |
| Benzo[a]pyrene | 0.114 ppb | EPA RSL |
| Other PAHs (e.g. fluoranthene, anthracene, chrysene, pyrene, naphthalene) | Varies (usually in ppb) | EPA RSL |
| TPH (Total) | Varies | CA Regional Boards |
| GRO (C6–C10) | ~100 | CA Water Board soil guidance |
| DRO (C10–C2M8) | ~500 | CA Water Board soil guidance |
| PFOS | 0.0063 | San Francisco Water Board Guidance |
| PFOA | 0.019 ppb | San Francisco Water Board Guidance |
| Asbestos | No safe threshold | EPA |
| TCE | 480 ppb | EPA RSL |
Department of Toxic Substances Control (DTSC) — Cal EPA State
dtsc.ca.gov/human-health-risk-hero · uses risk-based levels rather than generic screening limits
Environmental Protection Agency (EPA) — Federal Federal
epa.gov/risk/regional-screening-levels-rsls-generic-tables
A unit of measure used to describe extremely small concentrations of a contaminant in a larger substance.
Example1 ppb of fluoranthene means 1 part fluoranthene per every 1,000,000,000 (1 billion) parts soil (or 1/1,000,000,000).