HAZWOPER 24 cheat sheet

HAZWOPER is 29 CFR 1910.120 for general industry; construction counterparts are 29 CFR 1926.65. The standard is triggered when employees handle hazardous waste, work at uncontrolled hazardous waste sites (e.g., CERCLA/NPL sites), or respond to hazardous substance releases.

Training hour tiers: 40 hours for general site workers, 24 hours for occasional site workers who stay in clean areas and do limited work, 8 hours for supervisors, and 24 hours for emergency responders at the awareness level.

24-hour workers must have 8 hours of supervised field experience plus 1 day of supervised training before site work; annual 8-hour refresher is required for all tiers, and a break longer than 12 months requires retraining.

Site characterization follows a phased approach: preliminary assessment, site inspection, remedial investigation, and feasibility study. Sampling plans specify analytes, detection limits, sample locations, and QA/QC (blanks, duplicates, spikes).

The site safety and health plan (HASP) is required for all sites and must include a hazard analysis, employee training assignments, PPE selection, monitoring, decontamination, and medical surveillance provisions.

Health and safety plan review occurs before entry and whenever site conditions change (new contaminants, new tasks, or monitoring results exceeding action levels).

The written safety program includes an emergency response plan with site map, evacuation routes, alarm signals, and a designated emergency coordinator.

Employee rights include access to exposure and medical records (29 CFR 1910.1020), hazard communication information, and the right to refuse unsafe work without retaliation.

Dose-response relationship: response magnitude depends on dose (concentration × duration). The threshold limit value (TLV) and permissible exposure limit (PEL) are occupational exposure benchmarks; PELs are legally enforceable, TLVs are advisory.

Routes of exposure are inhalation, dermal absorption, ingestion, and injection. Inhalation dominates at most sites, but dermal absorption is significant for solvents and pesticides, and ingestion can occur via contaminated hands and food.

Gases and vapors: vapor density relative to air determines accumulation (heavier-than-air vapors pool in low areas); vapor pressure indicates volatility; the lower explosive limit (LEL) and upper explosive limit (UEL) define the flammable range.

Oxygen deficiency is defined as below 19.5% O2; oxygen enrichment above 23.5% increases fire risk. Confined space atmospheres must be tested for oxygen, flammables, and toxics before entry.

Toxic endpoints: acute effects (irritation, narcosis, asphyxiation) versus chronic effects (carcinogenicity, neurotoxicity, organ damage). Carcinogens include benzene, vinyl chloride, and asbestos.

Physical hazards at hazardous waste sites: slips/trips, heat and cold stress, noise, electrical, excavation collapse, and heavy equipment traffic. Heat stress is a leading cause of field injuries.

Corrosives cause tissue damage by pH extremes; oxidizers (e.g., nitrates, peroxides) can ignite combustibles; water-reactive materials (e.g., alkali metals) release flammable gas on contact with moisture.

Chemical incompatibility: keep oxidizers away from flammables, acids away from cyanides and sulfides (which release toxic gas), and avoid mixing waste streams that generate heat or gas.

Site control zones: exclusion zone (hot zone) where contamination is present, contamination reduction zone (warm zone) for decontamination, and support zone (cold zone) for administration and clean operations.

The buddy system requires at least two workers in the exclusion zone, with a backup team and a site safety officer monitoring entry and exit.

Decontamination methods: physical removal (brushing, scraping), washing with detergent and water, solvent rinses, and vapor/air drying. Decon is performed on personnel, PPE, and equipment before leaving the warm zone.

Personnel decon sequence: remove outer PPE, wash boots and gloves, remove suits, wash hands and face, and shower when required. Contaminated wash water must be contained and disposed of as hazardous waste.

Levels of protection: Level A (fully encapsulating suit with SCBA), Level B (chemical-resistant suit with SCBA), Level C (chemical-resistant suit with air-purifying respirator), Level D (work uniform, no respiratory protection).

Work practices: minimize contact with contaminated surfaces, avoid kneeling or sitting on the ground, do not eat, drink, or smoke in contaminated areas, and change gloves when torn or heavily contaminated.

Equipment decon includes removing gross contamination, washing, rinsing, and drying; sampling equipment should be decontaminated between sampling locations to prevent cross-contamination.

Site control also includes a site map, entry logs, communication systems, and defined emergency exit routes and assembly points.

Respiratory protection hierarchy: engineering controls first, then work practices, then respiratory protection. Air-purifying respirators (APRs) are used only when contaminants are known, at concentrations below IDLH, and oxygen is at least 19.5%.

Atmosphere-supplying respirators (SCBA or supplied air) are required in IDLH atmospheres, oxygen-deficient atmospheres, and when contaminant concentrations exceed APR cartridge capacity or are unknown.

Assigned protection factor (APF) is the expected protection level: half-mask APR APF 10, full-face APR APF 50, full-face supplied-air APF 1000, and SCBA APF 10,000. Required protection is the contaminant concentration divided by the APF.

Respirator fit testing: initial fit test before use, annual fit test thereafter, and fit test after changes in facial features or weight. Both qualitative and quantitative methods are acceptable; user seal checks are performed before each use.

Respirator cartridge change schedules are required for gases and vapors; change when breakthrough occurs, when odor is detected, or per the manufacturer's schedule, whichever comes first.

Chemical-resistant clothing selection depends on chemical breakthrough time, permeation rate, and degradation. Butyl rubber resists many solvents; nitrile resists oils; neoprene resists acids and caustics.

PPE inspection before each use: check suits for tears and seam integrity, gloves for pinholes, and respirator components for cracks or missing valves. Damaged PPE must be removed from service.

Heat stress from PPE: impermeable suits prevent evaporative cooling; monitor heart rate, body temperature, and symptoms, and use work-rest cycles with fluid replacement.

Monitoring hierarchy: direct-reading instruments (photoionization detector, combustible gas meter, colorimetric tubes) screen for flammables, oxygen, and volatile organics; laboratory analysis confirms specific contaminants.

Monitoring plan: specify instruments, calibration frequency, action levels, and monitoring locations (breathing zone, source area, perimeter). Calibrate instruments before each use per manufacturer instructions.

Action levels: if monitoring exceeds the action level, stop work, reassess, upgrade PPE, or evacuate. The plan must define the action level for each contaminant.

Combustible gas meters read percent LEL; readings above 10% LEL require evacuation or ventilation. Oxygen meters must be calibrated in clean air; readings below 19.5% or above 23.5% are unsafe.

Photoionization detector (PID) lamps respond to volatile organic compounds; response varies by compound, so PID readings are screening values, not direct concentration measurements.

Medical surveillance is required for employees exposed above the PEL for 30 or more days per year, employees exposed to carcinogens, and employees who wear respirators. It includes baseline and periodic exams, medical history, and biological monitoring.

Medical records must be kept for the duration of employment plus 30 years; exposure records for 30 years. Employees must be informed of monitoring results within 15 days of receipt.

Medical clearance for respirator use is required before fit testing; a physician evaluates the questionnaire and determines fitness, with follow-up exams as needed.

Emergency response levels: Level 1 is a release that can be controlled by the facility's own trained responders; Level 2 requires outside assistance; Level 3 requires full-scale community response.

First responder actions: recognize the hazard, isolate the area, notify, and evacuate. Do not attempt rescue or containment without training and PPE appropriate to the hazard.

Spill containment techniques: diking with absorbent booms, blocking drains, and using containment berms. Containment prevents spread to soil and water and reduces the volume requiring disposal.

The emergency response plan must include pre-emergency planning, personnel roles, lines of authority, communication, evacuation routes, and decontamination procedures.

Incident command system (ICS) structure: incident commander, safety officer, operations, planning, logistics, and finance. Responders operate within a unified command.

Evacuation versus shelter-in-place: evacuate when the release is spreading toward occupied areas; shelter-in-place when evacuation would move people through the hazard.

Post-emergency: decontaminate responders, account for all personnel, document the incident, and conduct a critique to identify improvements.

Emergency response training must include drills and exercises, and the plan must be reviewed and updated when site conditions or personnel change.