FUELS: The Naphthalene Question – Its Origins & Impact –

1. FUELS: The Naphthalene Question– Its Origins & Impact – JOHN P. HINZ Health Risk Assessment Toxicologist U.S. Air Force School of Aerospace Medicine/OEHR Air Force Research Laboratory Wright-Patterson AFB, OH

2. THE NAPHTHALENE QUESTION- origins - • What started all the fuss? What does it all mean? • NTP: two important bioassays • Mouse (1992) – cytotoxicity with lung neoplasia • Rat (2000) – cytotoxicity with unusualnasal neoplasia • “Reasonably anticipated to be a human carcinogen” • EPA-IRIS (2004): fast-tracked naphthalene’s re-exanimation • Predicts de minimus risk  2 ppt • 20X the potency of benzene – an established human carcinogen • Cancer determination: USAF mission & stewardship impact? • Exposure guidance – labels fuels/lubes carcinogenic? • Operations – ESOH; emissions compliance; restoration? • Stakeholders  MOA research program … are we like rats?

3. THE NAPHTHALENE QUESTION- origins - • Key question – how much is in our fuels? • Federal agency authority – EPA vs. OSHA • EPA/NCEA & IRIS with authority for guidance • Risk assessment  exposure guidance   compliance values • OSHA with authority forregulation • 29CFR 1910.1000 et al. [1910.1200 (d) (5) (ii)] If carcinogen content ≥ 0.1% (vol% or wt%), then the mixture is considered to be carcinogenic … and must be so labeled Crude oil ≥ 0.1% Gasoline 0-5% Jet fuel 1-3% Additives/lubes/blends ≤ 10% OSHA’s 0.1%  a regulatory “bright line” • Key question – how much is in our fuels?

4. THE NAPHTHALENE QUESTION- origins - • Previous information – issues & analyses • “Mil Specs” for jet fuel performance-based (<25% aromatics) • Constituent content varies with fuel source/supplier  swift KITA! • MSDS sheets generic  express range of values • TPHCWG monographs  data based on limited sample sets • CRC “World Fuel Sampling Program”  broader data set but generic • CRC & API experts  analytical results hostage to analytical technique • Most reports  TOTAL naphthalenes, including substituted forms • Substituted forms (~15 in jet fuel)  exaggerate published data  biological activities unknown • EPA/IRIS target  specifically naphthalene • USAF analytical target  specifically naphthalene • Pentagon  must know with precision the N-content of our fuel • Analytical program designed & approved

5. THE NAPHTHALENE QUESTION- origins - • Jet Fuel(s) Analytical Program • Specifically identify and quantitate benzene ………………………… human carcinogen naphthalene ……………………. current EPA target 1-methyl naphthalene ………… IRIS file, future target ? 2-methyl naphthalene …………. IRIS file, future target ? total naphthalenes – (D1840) … methods & N comparison total naphthalenes – (D6379) … methods & N comparison total aromatics – (D5186) …….. methods & N comparison • Different analytical techniques express results as vol% vs. wt% For comparison - convert all results to one convention reference to OSHA 0.1% threshold • Surprise issue … “the density follies”! Reference literature – 10 values for density of naphthalene impact on vol% vs. wt% conversion  OSHA threshold

6. THE NAPHTHALENE QUESTION- origins - Characterizing “generic” jet fuel stock-1stock-2stock-3stock-4stock-5blend (units) [density] [0.799] [0.825] [0.808] [0.806] [0.800] [0.806] benzene 200 2.0 110 28 17 66 µg/mL naphthalene 2560 726800 1390 556 1160 µg/mL 1-methyl-N 2070 863 1290 1300 1030 1280 µg/mL 2-methyl-N 4170 1340 1710 2230 1100 2080 µg/mL t-Ns (D1840) 1.5 1.3 1.2 0.6 0.6 1.2 vol% t-Ns (D6379) 1.9 1.4 1.4 1.3 0.6 1.3 vol% t-aromatics 16 19 20 19 20 19 vol% (D1319) --------------------------------------------------------------------------------------------------- • Overall, N-content of most fuels exceeded the OSHA threshold.

7. THE NAPHTHALENE QUESTION- origins - Questions?