Fundamentals of Industrial Hygiene 6th Edition Part III: Recognition of Hazards Chapter 6: Industrial Toxicology Compiled by Allen Sullivan, Assistant Professor, Safety and Health Management Central Washington University

Definitions Definitions toxic effect toxicity dose hazard route of entry (inhalation, dermal, ingestion) quantity of exposure (amount and duration) characteristics of substance (physical state, size, pH) physiological state (state of health, pre-existing conditions) environmental variables (presence of other substances)

Route of Entry Inhalation Skin Absorption Ingestion Injection upper respiratory tract lower respiratory tract Skin Absorption skin thickness temperature perspiration Ingestion Injection

Dose–Response Relationship Dose C  T = K concentration (C) time duration (T) constant (K) Response threshold concept potency toxicity cumulative effects exposure thresholds NOAEL (No Observable Adverse Effect Level) LOAEL (Lowest Observed Adverse Effect Level)

Lethal Dose (LD) Lethal Dose Lethal Concentration (LC) Evaluation bell-shaped Curve LD50 LD0 LD100 usually mg/kg Lethal Concentration (LC) airborne usually mg/m3 or ppm Evaluation

Timing: Exposure and Effect Acute Effects and Acute Exposures rapid onset short duration rapid absorption Chronic Effects and Chronic Exposures slow to develop long duration and/or frequent recurrence

Airborne Contaminant Exposure Irritants primary irritant secondary irritant Allergens hypersensitivity v. hypersusceptibility Systemic Toxins Asphyxiants simple asphyxiants chemical asphyxiants

Airborne Contaminant Exposure (cont.) Organ-Specific Effects central nervous system depressants cardiac sensitization neurotoxic effects pulmonary effects particulates not otherwise specified (PNOS) heavy metals carcinogenesis carcinogen carcinogenic potential

Airborne Contaminant Exposure (cont.) mutagenesis reproductive toxicity teratogenesis pregnant women in the workplace

Basis for Workplace Standards Chemical Analogy Animal Experimentation exposure standards screening procedures problem areas In-vitro Testing Human Epidemiological Studies descriptive studies retrospective studies prospective studies

Federal Regulations Occupational Safety and Health Act of 1970 (OSHAct) right-to-know regulation permissible exposure limits (PELs) toxic substances list Toxic Substances Control Act of 1976 (TSCA) NIOSH Standards criteria documents recommended exposure levels (RELs) current intelligence bulletins (CIBs) OSHA Standards

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLV®) limitations of TLVs (OELs) time-weighted average ceiling values STELs mixtures antagonistic potentiation (synergistic) carcinogens (carcinogenic potential) physical factors (judgment) unlisted substances Selection of TLVs (OELs) CaTa + CbTb + … CnTn = TWA 8 C1 + C2 + C3 + ... = 1 T1 T2 T3

Biological Testing Biological Testing biological analysis body burden amount in circulation amount excreted benefits of biological analysis over air sampling types of biological analyses unchanged substances metabolites levels of naturally occurring substances urine, blood, and breath analyses