M2 · Site Hazard Assessment

Module Two. Site Hazard Assessment. Look at the job before you touch it. The assessment is the first control on every site. Module One was about seeing hazards. This module is the step that turns what you see into a plan. Assessing the site before work starts. Here is why it exists. Almost every bad outcome on our jobs traces back to an assessment that was skipped, rushed, or kept in someone's head instead of on paper. In the next few minutes we will cover four things. What we gather before we leave the yard. How to survey from the outside before you walk in. Naming the hazards so the right controls follow. And the unknown-substance rule, testing, and work zones.

Let's start with the order of things. PPE is the last control, not the first. The assessment decides what the day looks like. It is tempting to gear up and get moving. But a decision made before you understand the site is a guess. On a private-side cleanout, the site is often somebody else's mess, with no paperwork and no history. Which is exactly why we look first. Three things the assessment protects. Your health, from the exposures you never chose to take. The crew, working to one plan instead of three versions. And the job, work that holds up if anyone asks what we did and why. Assessment in writing, before entry, every time. When it lives in someone's head, it is not an assessment. It is a habit that has not failed yet.

Now, scope. What assessment means here. This is not a forty-hour site characterization. It is a practical, documented look before the work starts. The full HAZWOPER site characterization is written for large hazardous-waste sites. Ours is scoped to a private-side job. Know what you are walking into. Name the hazards. Set the controls. Write it down. What it is. A short, structured look. Gather, survey, name, control, document. What it is not. Sampling every pile, lab work, or a full engineering study. When a job needs that, we escalate. Where a job legally falls under twenty nine C F R nineteen ten point one twenty, the regulatory requirements still apply. This module supports awareness-level, scoped private-side work.

Step one. Gather what is known before you drive out. Most of what decides the day is knowable before anyone puts a glove on. Ask, and read, before you arrive. Client and property. Who owns it, and what they told us about it. Prior use. Residence, farm, shop, auto body, camp. Old uses leave residues. Known materials. Asbestos, lead paint, fuel, chemicals, medical waste. Drums or waste reported. If there are any, they set the tone for the whole job. Utilities and structures. Power, gas, water, and unstable floors, roofs, or ground. And write it down before you leave. A claim you did not record is a claim you cannot defend.

Step two. Survey from outside before you walk in. Look before you walk. The first lap of a site is done on your feet, around the edge, not in the middle of it. Walk the perimeter first, and read the site from its edge. Access. How you get in, and more importantly, back out. Terrain. Slope, unstable ground, standing water. Structures. The condition of buildings and sheds, and what is inside them. Containers. Drums, jugs, pails. Marked or not. Staining and smells. Discolouration, dead vegetation, odours. Animals. Living and dead. Where they are is where hazards are. You are building the picture, not solving the job. Curiosity happens from a distance.

Step three. Name the hazards in categories. Sorting what you find tells you which control applies. Same logic as Module One, applied to a whole site. Chemical. Unknown drums, solvents, fuels, staining. Biological. Feces, sharps, medical waste, decay, sewage. Physical. Sharps and glass, unstable piles, heat, slips, structure. Atmospheric. Confined or enclosed spaces. Anything that could change the air. Structural. Floors, roofs, walls, excavations that may not hold. And overlapping. A drum of unknown liquid in a collapsed shed is several categories at once. Name the category, and the control follows. Skip the naming, and you pick PPE by habit.

Now the one rule. The unknown-substance rule. Any container you cannot identify is hazardous until it is proven otherwise. Stop. Do not touch. Characterise from a distance. Escalate. Do not open it, tip it, or smell it to work out what is inside. Mark and isolate. Keep everyone back, and stay upwind. Characterise from a distance. Labels, markings, shape, location, and any paperwork. Then escalate. Supervisor, location, photo, what you saw. Let someone qualified decide. This is the rule you sign to at the end of the module, same as Module One. It does not change job to job.

Before entry. Testing before you enter. Some spaces have to be tested before anyone steps in. The assessment decides when. You do not need to test every job. You do need to test before entry when the space could hold something the air will not show you. Confined or enclosed spaces. Tanks, vaults, pits, crawlspaces, vessels. Suspected gases or vapours. Fuel, solvents, decay, sewage. And any space where the plan depends on the air being safe. What a basic meter tells you. Oxygen, flammables, and common toxics. A four-gas meter covers oxygen, L E L, carbon monoxide, and hydrogen sulfide. It does not cover everything, and it is only as good as its last calibration. Test order. Oxygen first, then flammables, then toxics. If a space cannot be made safe, it does not get entered. It gets escalated.

Layout. The work zones. Three zones keep what is dirty away from what is clean, even on a small cleanout. Exclusion. The work area itself. Only what has to be in there is in there. Contamination reduction. Where decontamination happens. Gear off, waste contained, no crossing over. Support. The clean side. Staging, tools, rest, first aid. Even on a private-side cleanout, the layout matters. Set the zones before work starts, keep the flow one way, and keep the clean side clean. The zone line is where contamination is stopped from leaving the job.

Controls. Turn the assessment into controls. From hazard to control, in order. The assessment picks the PPE, not the other way round. First, elimination or substitution. Can the hazard be removed or worked around instead of worked in. Second, engineering. Ventilation, containment, equipment that keeps people away from the source. Third, work practice. Procedures, sequencing, distance, housekeeping, and time. And last, PPE. The last line, chosen to match the named hazard. The test of a good assessment. Someone who was not there can read it, and see why the crew wore what they wore, and did what they did.

On paper. Write it down, and use the stop rule. If it is not written down, it did not happen. And anyone can stop the job. The assessment is a record as much as a plan. What goes in it. What was known before arrival, and who said it. What the survey found, hazard by hazard. The controls and PPE chosen, and for which hazard. Anything unknown, marked, and escalated. And the stop rule. Anyone on the job can stop work when something does not match the plan. That is not a delay. It is the assessment doing its job.

Recap. Five points to carry onto the next job. One. Assessment first, in writing, before entry. Two. Gather what is known before you drive out. Three. Survey from the outside before you walk in. Four. Name the hazards in categories. The categories pick the controls. Five. Unknown means stop, do not touch, characterise from a distance, escalate. Next module. Toxicology and Routes of Exposure. What these hazards do once they get into the body, and how they get in.