Regulation and Risk Assessment of 1,4-Dioxane - Environmental Investigation and Remediation - page 268

TABLE 6.1 (continued)
State, Federal (EPA), and International Regulatory Guidelines, Action Levels, and
Remediation Targets for 1,4-Dioxane as of 2007
EPA National Center for Environmental Assessment [2]
Health-based advisory level (tap water): 3 μg/L
CSF: 0.011 (mg/kg d) -1
EPA Region 3: Risk-based concentrations [2]
Tap water: 6.1 μg/L
Soil (industrial): 260 mg/kg
Soil (residential): 58 mg/kg
Soil (groundwater protection): 0.0013-0.0026 mg/kg
EPA Region 6 screening levels [2]
Tap water: 6.1 μg/L
Soil (industrial): 170-520 mg/kg
Soil (residential): 44 mg/kg
EPA Region 9 PRG [2]
Tap water: 6.1 μg/L
Soil (industrial): 160 mg/kg
Soil (residential): 44 mg/kg
Canada: Guidance value [11]
Drinking water: 30 μg/L
Japan: Drinking water quality standard [18]
Drinking water: 50 μg/L
WHO: Guidelines for drinking-water quality [23]

Drinking water: 50 μg/L

Sources: [1] ADEC (2007); [2] AFCEE (2007); [3] Mississippi-DEQ (2002); [4] NMED (2006); [5] NYSDEC (2006); [6]
NCDENR (2005); [7] OEPA (2004); [8] Oklahoma DEQ (2003); [9] SDENR (2007); [10] NHDES (2004); [11]
Health Canada (2005); [12] Montana-DEQ (2002); [13] OEHHA (2000); [14] ATSDR (1992); [15] ATSDR (2005a);
[16] VDEQ (2007); [17] Washington Administrative Code (2003); [18] Japanese Ministry of Health, Labour, and Welfare
(2003); [19] MADEP (2007); [20] ODEQ (2007); [21] TELL (1996); [22] HDOH (2005); and [23] WHO (2005).
Notes: States with no standards (not listed in Table 6.1 ) will typically evaluate groundwater or surface water on a case-by-
case basis after 1,4-dioxane is detected. However, these states typically do not require testing, and when testing is
performed, detection limits are often very high (50-100 ppb). Therefore, 1,4-dioxane has not manifested as a signii -
cant problem in these states even where chlorinated ethanes are present.

a

One-day health advisory: The concentration of a chemical in drinking water that is not expected to cause any adverse
noncarcinogenic effects for up to one day of exposure. The one-day health advisory is normally designed to protect a 10 kg
child consuming 1 L of water per day.

Regulations governing acceptable levels of 1,4-dioxane in drinking water and cleanup levels for
1,4-dioxane in soil and groundwater vary widely. A compilation of state, federal, and international
regulatory guidelines, action levels, and remediation targets as of 2007 is presented in Table 6.1.

6.1.2 B ASIS FOR S TATE R EGULATIONS OR G UIDELINES : C OLORADO ,
C ALIFORNIA , C ONNECTICUT , AND M ICHIGAN
Chapter 5 provides a comprehensive review of the 1,4-dioxane toxicology knowledge base. The
primary exposure routes leading to 1,4-dioxane toxicity are ingestion of contaminated drinking
water and inhalation, which is likely to occur only in occupational settings. Liver and kidney toxicity
are the primary noncancer health effects associated with exposure to 1,4-dioxane in humans and