Regulation and Risk Assessment of 1,4-Dioxane - Environmental Investigation and Remediation - page 288

TABLE 6.16
Recommended or Regulated Inhalation Exposure Limits for 1,4-Dioxane

Level
(ppm)/(mg/m 3 ) Agency Context References

NIOSH 500/1800 IDLH NIOSH (2005)

OSHA 100/360 PEL; 8-h TWA OSHA (2007)

United Kingdom 25/91 Long-term exposure limit: 8-h TWA UKHSE (2007)

100/366 STEL: 15-min reference period

South Africa 25/90 OEL: 8 h SAIOH (2007)

100/360 OEL: 15-min peak

Finland 25/91 HTP: 8-h exposure level STM (2005)

40/150 HTP: 15-min exposure level

Germany 20/72 MAK: 8 h Greim (2000) (2005) a

40/144 MAK: 15 min—based on eye irritation

the Netherlands 12/43 MAC: 8 h ECB (1999)

24/66 MAC: 15 min

Argentina 20/72 CMP ILO (2007)

Hungary 10/36 Occupational exposure level: 8 h ILO (2007)

National Authority for
Occupational Safety
and Health (Ireland)

20/72 OEL value: 8 h (reference period) NAOSH (2002)

France 10/35 VME: 8-h exposure level INRS (2006)

40/150 VCLT: Level 15-min exposure level

Japan 10/36 Occupational exposure level: 8 h JSOH (2007)

Swedish Work
Environment Authority

10/35 LLV: 8 h SWEA (2005) (1996) a

25/90 CLV: 15 min

United States 2/7.2 MRL: 14-day inhalation ATSDR (2004)

1/3.5 MRL: 365-day inhalation

Note : CMP, concentración Máxima Permisible; HTP, Haitallisiksi Tunnetut Pitoisuudet (concentrations known to be
hazardous); NIOSH, U.S. National Institute for Occupational Safety and Health; OSHA, U.S. Occupational Safety
and Health Administration; VCLT, Valeurs Limites Court Term (short-term exposure limits, i.e., STELs); VME,
Valeur Limite de Moyenne d'Exposition (average exposure limit values).

a

Dates in parentheses indicate the year in which the exposure limit was i rst adopted.

Spots rule requires all facilities emitting more than 85 pounds of 1,4-dioxane per year to prepare
emission inventory plans and reports (CARB, 2008). Connecticut's emission regulation stipulates
that 1,4-dioxane emissions must not exceed an 8-hour hazard limiting value of 450 μg/m 3 or a half-
hour maximum of 2250 μg/m 3 (CDEP, 2002).
Verschueren (2001) offered the following equation to convert the mass concentration of an air-
borne contaminant ( W / V ) to its volume concentration ( C vol ):

WRT

C = , (6.7)

vol

VPm

where C vol is the volumetric concentration of the contaminant (in ppb), W is the mass of the
compound present in volume V (in grams), V is thevolume of contaminated air (in m 3 ; V

= 1 m 3 ),