Table 1.
Exposure limits and guidelines for naphthalene.
| Organization | Reference Level | Unit | Interpretation | Year | Ref |
|---|---|---|---|---|---|
| Environmental | |||||
| Environmental Protection Agency (EPA) | 3 | μg m−3 | Inhalation RfC | 1998 | [17] |
| Agency for Toxic Substances and Disease Registry (ATSDR) | 3.6 | μg m−3 | Inhalation MRL (Chronic) | 2005 | [30] |
| Office of Environmental Health Hazard Assessment (OEHHA), California | 9 | μg m−3 | Inhalation REL (Chronic) | 2000 | [31] |
| Office of Environmental Health Hazard Assessment (OEHHA), California | 3.4 × 10−5 | per μg m−3 | Inhalation Unit Risk | 2009 | [22] |
| Michigan Department of Environmental Quality (MDEQ) | 3 0.08 0.8 |
μg m−3 | ITSL (24 hr) IRSL (cancer risk of 10−6) SRSL (cancer risk of 10−5) |
2004 | [32] |
| Occupational | |||||
| Occupational Safety & Health Administration (OSHA) | 50 | μg m−3 | PEL (TWA) | 2001 | [33] |
| National Institute for Occupational Safety and Health (NIOSH) | 50 75 |
μg m−3 | REL (TWA) REL (STEL, 15 min) |
2005 | [34] |
| American Conference of Governmental Industrial Hygienists (ACGIH) | 50 75 |
μg m−3 | TLV (TWA) TLV (STEL, 15 min) |
2009 | [35] |
Notes: RfC = Reference Concentration; MRL = Minimal Risk Level; REL = Reference Exposure Level; ITSL = Initial Threshold Screening Level; IRSL and SRSL = Initial and Secondary Risk Screening Levels; PEL = Permissible Exposure Limit; REL = Recommended Exposure Limit; TLV = Threshold Limit Value; TWA = Time Weighted Average; STEL = Short Term Exposure Limit. This Table does not include the lower levels given by EPA [18] in a “do not cite or quote” draft document discussed in the text. Ref = Reference.