Misuse of Exposure Reporting in Acute Risk Assessment John S. Morawetz International Chemical Workers Union Council/UFCW Center for Worker Health & Safety Training Cincinnati, Ohio (513)

Acute Exposure Guideline Levels Since 1996 the EPA has convened meetings of a National Advisory Committee for Acute Exposure Guideline Levels (AEGLs) Committee of Toxicology of the National Research Council and National Academy of Sciences “Once in a lifetime short term exposures” for general public

Health Outcomes AEGL-1 Notable discomfort AEGL-2 Irreversible or serious, long lasting effects including impaired ability to escape AEGL-3Death or life threatening

Time Periods Levels are set for 5 time periods: 10 and 30 minutes, 1, 4 and 8 hours for each health outcome Total of 15 levels per chemical

Application General population including infants, children, asthmatics and other susceptible groups Unlike occupational recommendations, intended for once in a lifetime exposure

Caveats Primary -Control Exposures; hierarchy of controls Substitution Pollution Prevention Need Multi disciplinary efforts Toxicologists, Physicians, Epidemiologists, Industrial Hygienists, Statisticians, Engineers

Caveats “Intended to be used as planning tools” “when an actual chemical emergency occurs, there often is no time to measure airborne concentrations ” “Not to be used as safe limits for routine operations or definitive delineators between safe and unsafe exposure conditions” (AIHA, ERPG handbook, 2000)

AEGL Committee’s misuse of human studies Inaccurate reporting in draft report –Time period of sample –Area vs. personal vs. bulk –TWA vs. instantaneous –Anecdotal vs. case or full study Rejection of reconstruction studies Inappropriate use of range of data

Inaccurate Reporting Inaccurate summary of level –“No exposure measurements” SOP –Incorrect range reported - phosphine Time period associated with measurement –“No exposure time noted” phosphine (Wilson) –Range of levels with no time period trichloroethane – fatality reconstruction methanol – NIOSH HHE

Inaccurate Reporting Area vs. personal samples –Propylene Glycol Dinitrate –Hydrogen Cyanide (Leeser) Reported only "routine" instantaneous samples (1 to 3 ppm) rather than available personal samples

Inaccurate Reporting Area vs. personal samples –Methanol – AEGL stated "measured in the vicinity of the duplicators". – NIOSH HHE (1981) states "Breathing zone samples were collected for methyl alcohol vapors over a 25 minute sampling period".

Inaccurate Reporting Bulk vs. Area vs. Personal samples – “raw acetylene contained less than 3 ppm “ Used as a personal exposure – phosphine Case reports described as anecdotal - phosphorous trichloride - trichlorethylene

Rejection of fatality reconstruction studies Simulation of task with sampling Phosphine (Hager) Trichloroethane

Inappropriate use of range of data Attributed to which exposure level? AEGL - Single Upper limit of range Examples: Propylene Glycol Dinitrate –Maximum value of 400 inst. Samples Hydrogen Cyanide –34 samples in 8 job titles

Hydrogen Cyanide Exposures by Job Title Leeser, 1990

Summary Multi disciplinary Risk Assessment committees –Draft reports –Committee discussion and recommendation –Final approval Accurate summary of original articles Uranium Hexafluoride

Composition of Committee Preponderance of one expertise Bias towards one expertise

Current Issues – Hydrogen Cyanide – Leeser: used as primary study – Grabois study, 1954 – Industrial Hygiene survey with NO health survey – Occupational Application of AEGLs – Emergency Response