A Preliminary Quantitative Risk Assessment of Inhalation Exposure to Diethanolamine and Respiratory Effects

Details

• Personal Author:
  Pandalai, Sudah P.
• Description:
  Diethanolamine (DEA; MW=105.14 g/mol) is used in various industrial chemical processes. This work describes a preliminary quantitative risk assessment of DEA inhalation exposure and respiratory effects to extrapolate to the occupational context. The best available data identified were from a low dose inhalation exposure study (Gamer et al. 2008) using a head-nose apparatus to dose groups of 13 Wistar rats (strain CrlG1xBr1Han:WI) of each sex. Animals were exposed to 0, 1.5, 3, or 8 mg/m3 of aerosolized DEA for 6 hours/day, 5 days/week, for a total of 30 hours/week, with exposures on 65 of 99 days (90-day study). The endpoint laryngeal epithelial squamous metaplasia in male rats had sufficient non-zero dose group counts of 0, 0, 3, and 9 with increasing dose and a significant CochranArmitage one-sided exact trend test (p<0.0001). This endpoint was deemed appropriate for dose-response modeling. Frequentist and model average (MA) approaches used the U.S. Environmental Protection Agency (EPA) Benchmark Dose Software version 3.2.0.1, with a 10% benchmark response, estimated background, extra risk, and 95% confidence interval. To extrapolate to a 40-hour work week, the point of departure (PoD) was multiplied by a factor of 30/40, or 0.75. Since DEA is an aerosol, the PoD was also multiplied by a dose adjustment factor equal to a regional dose deposition ratio of 0.08. Uncertainty factors (UFs) were used to account for interspecies, interindividual, and subchronic to chronic uncertainty and variability, following Dankovic et al. 2015. It was assumed that laryngeal epithelial squamous metaplasia is a site of contact effect, and as such is assumed to have similar toxicokinetic effects across species. The toxicokinetic component of the interspecies and interindividual uncertainty factors were set to 1, with the toxicodynamic component values of 2.5 for interspecies and 3.2 for interindividual UFs providing the basis of each total UF. The sub-chronic to chronic uncertainty factor was set to 3. The overall UF=24, calculated by multiplying individual UFs. The MA benchmark concentration (BMC) and benchmark concentration lower bound (BMCL) values for the endpoint of laryngeal epithelial squamous metaplasia in male rats were 2.3 mg/m3 and 1 mg/m3, respectively. The viable, recommended model, based on standard criteria from the U.S. EPA for the frequentist suite, was the multistage degree 3. This model had the lowest Akaike Information Criterion value of all frequentist models (37.1). The BMC and BMCL values for this model were 1 mg/m3 and 0.7 mg/m3, respectively. Although these values are lower, the MA values consider information available from all individual models contributing to the MA. The MA approach thus considers a broader set of dose-response relationship information than that considered by an individual model. The MA results were used to determine a human equivalent concentration (HEC). This gave an 8-hour time weighted average HEC, using the MA BMCL value, of [(1 mg/m3) * 0.75 * 0.08]/24=0.0025 mg/m3 (0.58 ppb). Similar calculation using the BMC=2.3 mg/m3 results in a HEC of 0.006 mg/m3 (1.4 ppb). The resulting 8-hour time weighted average value of 0.58 ppb has relevance for inhalation exposure to DEA in the occupational setting. [Description provided by NIOSH]
• Subjects:
  Animals Occupational Health Respiratory System Safety
• Keywords:
  Animal Studies Diethanolamine Inhalation Studies Models Risk Assessment Toxic Effects
• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DSI - Division of Science Integration
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  3 pdf pages
• Volume:
  192
• NIOSHTIC Number:
  nn:20067224
• Citation:
  Toxicologist 2023 Mar; 192(S1):440-441
• CAS Registry Number:
  Diethanolamine (CAS RN 111-42-2)
• Federal Fiscal Year:
  2023
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 62nd Annual Meeting & ToxExpo, March 19-23, 2023, Nashville, Tennessee
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:9e1d95a6895709da4ec717b46a8c105ee056206410d4f7d433cfd1ef5b5d16a334de0535b98546e3f94978dede76e87825710426475daee1d1c8a3e2cd92dcfc
• Download URL:
  https://stacks.cdc.gov/view/cdc/230672/cdc_230672_DS1.pdf
• File Type:
  [PDF - 1.10 MB ]