fundamentals of industrial hygiene 6 th edition part iii: recognition of hazards chapter 6:...
TRANSCRIPT
Fundamentals of Industrial Hygiene
6th Edition
Part III: Recognition of Hazards
Chapter 6:
Industrial Toxicology
Compiled by Allen Sullivan,
Assistant Professor, Safety and Health ManagementCentral 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• 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• 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 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
Biological Testing