1
Set the scene
Start with context
Fill the frame
2–3 ft for close-ups; keep ladders, cords and workers fully in view.
Signal words
DANGER, WARNING, and CAUTION signs — what each signal word means and when to use it
DANGER, WARNING, and CAUTION are signal words that rank how serious a hazard is. Under OSHA's sign rule, 29 CFR 1910.145, danger signs are only for immediate hazards and caution signs are for potential hazards or unsafe practices — the rule has no WARNING sign class. WARNING comes from ANSI Z535.2, the voluntary consensus standard: DANGER (red) marks a hazard that will cause death or serious injury if not avoided, WARNING (orange) one that could, and CAUTION (yellow) one that could cause minor or moderate injury. In construction, 29 CFR 1926.200 accepts the Z535.2-2011 designs. OSHA Scan does not rate your signs. It scans photos for hazards whose warning is weaker than the risk, and for signs that are hidden or blank. The free checklist below covers each signal word.
Photo scan: no account needed (you may be asked for the free phone Access Pass) · Template downloads: free account required
The signal word tells workers how serious the hazard is — so it has to match
Signal words exist so a worker can judge a hazard from across the room without reading the fine print. OSHA's general industry rule keeps the system simple: 29 CFR 1910.145 reserves danger signs for immediate hazards where special precautions are necessary, and caution signs for potential hazards or unsafe practices. ANSI Z535.2, the consensus standard most sign makers follow, adds WARNING between them — for hazards that could cause death or serious injury — and uses orange to set it apart. The construction rule accepts either the older ANSI designs or Z535.2-2011, so a construction site may properly carry all three words.
The mistakes that matter on a real site are mismatches. A caution floor stand beside an open trench understates a hazard that calls for a cover or guardrail, not just a sign. A danger label with nothing written under it raises the alarm without saying what the hazard is. And any signal word is useless when a hose or a cart hangs in front of it. OSHA Scan reviews a photo of the area and flags those conditions with a possibly related standard and a fix. It does not grade sign design; it shows you where the warning and the hazard don't line up.
How OSHA's two-level system and ANSI's three signal words fit together
OSHA's general industry sign rule recognizes two hazard levels on signs: danger and caution. It requires that danger signs for specific dangers not vary in design, that workers be told danger means immediate danger needing special precautions, and that caution signs be used only for potential hazards or unsafe practices. ANSI Z535.2 splits the upper level in two: DANGER for hazards that will cause death or serious injury if not avoided, and WARNING for those that could. It also adds NOTICE, in blue, for practices not related to personal injury, and pairs the personal-injury signal words with a safety alert symbol.
In practice, the choice comes down to two questions: how bad is the worst likely outcome, and how close are people to the hazard? Exposed live parts or a trench people walk past is a DANGER-level problem, and the first fix is a barrier, cover, or lock — the sign comes second. A wet floor or a low beam is a CAUTION-level problem. Whatever words you use, keep them consistent across the site so a red header always means the same thing. A routine photo scan helps you spot the places where the sign on the wall no longer matches the hazard in front of it.
How to choose between DANGER, WARNING, and CAUTION signs
Run through these steps before crews start — each one covers a visible gap the AI can help you catch.
- 1
Identify the hazard
Describe the hazard and who is exposed: what could happen, how badly someone could be hurt, and how close people work to it.
- 2
Control it first
Cover, guard, barricade, or lock out the hazard wherever a rule requires it. Signs add a warning; they don't replace protection.
- 3
Choose the signal word
Use DANGER for hazards that will cause death or serious injury, WARNING (the ANSI word) for those that could, and CAUTION for minor or moderate injury or unsafe practices.
- 4
Add the hazard and the action
Under the signal word, state the hazard and what to do in plain words, with a symbol and a second language if your workers need one.
- 5
Post, train, and re-check
Mount the sign where people approaching the hazard will see it, explain the signal words in training, and re-check signs regularly. A dated photo scan documents each check.
What a photo scan checks around your DANGER, WARNING, and CAUTION signs
A scan doesn't rate signal words, but it can see when a warning is weaker than the hazard next to it — or when no one can see the warning at all.
Warnings that understate the hazard
A caution stand at an open hole or an unguarded edge, where the rule calls for a cover, guardrail, or barrier rather than a sign.
Signs nobody can see
Hoses, carts, and stored material hung over or parked in front of signs, hiding the signal word or the message under it.
Hazards behind the sign
Blocked electrical panels, open pits, and missing guards that a sign points to but doesn't fix.
A fix for each finding
Each flagged item comes with a possibly related OSHA standard and a corrective action, ranked by risk, so the worst exposure gets fixed first.
Demo: the report a scanned photo comes back with
Scan a photo like the one above and this is the report you get — score, findings, OSHA references, and fixes. It is an illustrative example, clearly marked — not live scan data.
Example report
Illustrative — not live scan dataCompliance score
72
Lower means more potential hazards found
Score uses visible confirmed findings only. Not a safety certification.
3 confirmed · 0 need review · 0 positive
1 High1 Medium1 Low3 locked
1Floor trench left open with its grating leaned against the wall — only a caution floor stand beside it
HighPossibly related to protecting holes with covers or guardrails (29 CFR 1910.28(b)(3))
Observed condition: Someone stepping backward or walking past with a load can step straight into the trench. A caution stand signals a minor hazard, but OSHA's walking-working surfaces rule calls for a cover or a guardrail at a hole, not a sign.
Corrective action: Put the grating back as soon as work in the trench stops, or surround the opening with a guardrail or barricade while it has to stay open. Keep the floor stand as extra warning, not the only protection.
High confidence
2Utility cart loaded with scrap parked in front of the electrical panel
MediumPossibly related to working space around electrical equipment (29 CFR 1910.303(g)(1))
Observed condition: In an emergency, someone has to reach that panel fast to shut off power. A loaded cart in the way slows them down, and OSHA says the working space in front of electrical equipment may not be used for storage.
Corrective action: Move the cart and mark the floor in front of the panel as a keep-clear zone so nothing gets parked there again.
High confidence
3Orange warning sign on the cage partly covered by a coiled air hose
LowPossibly related to accident prevention signs that identify specific hazards (29 CFR 1910.145(a)(1))
Observed condition: The hose hangs across most of the sign's message area. Workers can see the signal word but not what the hazard is or what to do about it.
Corrective action: Hang the hose on a hook or reel away from the sign, and confirm what the sign warns about inside the cage.
High confidence
AI-generated analysisThese findings are potential hazards flagged by AI from a single photo. They are a starting point for your own review — not an official OSHA determination. Verify conditions on site with a qualified person before acting.
Try it free
Now scan your own photo — free
Upload a photo like the one above and get a compliance score and hazard count. No account needed to scan, though you may be asked for the free phone Access Pass — create a free account to unlock the full report.
- Hazards in your photo where the warning is weaker than the risk — like a caution stand at an open hole
- Danger, warning, and caution signs that are hidden, blank, or faded
- A possibly related OSHA standard and a fix for each finding — not a sign rating
Live OSHA hazard analysis
One lifetime free photo scanPhoto scan — freeVideo walkthrough scan — free account
1Upload photo
2AI analysis
3See report
Use the real site or facility name. If you save the scan after signup, it becomes the report name.
Three angles, one deeper scan
Only the wide shot is required — every extra angle gives the AI more places to look.
Required: Set the scene — one wide shot lets the AI sweep the whole area at once
Stand at the entry point and capture corner to corner: floors, ladders, scaffolds, and everyone at work
or choose from your library
Drop a job-site photo or walkthrough video
Click to upload, drag & drop, or snap a photo on site. Photos scan free with no signup and no card — you may be asked for the free phone Access Pass. Video walkthroughs (up to 3 min) run on a free account.
References relevant OSHA standardsPrivate - deleted in 48h unless you save it
Accuracy boosters
Small habits, sharper scans
2
Capture clearly
Make the frame usable
Light it right
Keep the sun or lights behind you — glare and shadows hide hazards.
Tap to focus
Tap the hazard on screen and hold still one second — blur can't be flagged.
3
Choose the useful view
Give the AI room to understand
Go landscape
Turn your phone sideways — a wider frame catches more of the scene.
No job-site photo handy?
or scan with video
Only upload photos you have permission to use, and avoid images showing personal, customer, or confidential information. Demo photos and results are held privately for up to 48 hours so you can save them to a free account; unclaimed photos are deleted automatically. Results are an AI-assisted preliminary review, not an official OSHA determination.
New: Video walkthrough scans
Record up to 3 minutes of your site — the AI extracts frames and categorizes findings with exact timestamps. Free account required.
Get the best results
Wide shot first
Stand at the entrance and photograph the entire work area so AI sees the full context
Hazard areas
Photograph elevated surfaces, equipment, electrical panels, and anywhere workers are active
Close-ups last
Move in close on anything damaged, missing, or that looks risky — the AI catches more detail
The 10-point DANGER, WARNING, and CAUTION sign checklist
How to choose the right signal word and keep it believable. The first four are free — create a free account to unlock the rest and scan your own site for sign problems.
- 1
Rank the hazard before you pick a sign
Ask what happens if someone ignores the warning. Death or serious injury that will happen points to DANGER, death or serious injury that could happen points to WARNING, and minor or moderate injury points to CAUTION.
- 2
Use DANGER only for immediate hazards
OSHA's sign rule limits danger signs to immediate hazards where special precautions are necessary (1910.145(c)(1)), and 1926.200(b) does the same in construction. Overusing DANGER teaches people to ignore it.
- 3
Use CAUTION for potential hazards
Caution signs warn of potential hazards or unsafe practices (1910.145(c)(2), 1926.200(c)) — not open holes, exposed live parts, or other hazards that can kill on contact.
- 4
Know that WARNING is an ANSI signal word
OSHA's general industry sign rule has no WARNING sign class. ANSI Z535.2 uses WARNING in orange for hazards that could cause death or serious injury, and OSHA's tag rule allows WARNING tags between caution and danger (1910.145(f)(7)).
Free printable templatePDF · US Letter
DANGER, WARNING, and CAUTION Sign Checklist
Use this form when you choose a new sign and when you walk the site to check existing ones. Rank the hazard first, then check that the signal word, colors, and wording fit it.
On the form
- 10 checklist items with Yes / No / N/A boxes and room for notes
- 4 points to confirm separately with records or a qualified person
- A corrective-action log and sign-off lines
- Federal references checked against the eCFR on October 10, 2026
A free account is required to download it.
Non-English documents are automated translations, not official OSHA translations. Citations, limits and names are kept as written.
OSHA Scan template — not an official government form and not legal advice.
Make DANGER, WARNING, and CAUTION signs for each site
Pick the signal word yourself, write the hazard message in English, Spanish, or both, and print on Letter, A4, or Tabloid paper. Your logo can appear on the sign, but it never changes the signal word colors. Once a sign is up, record where it's posted and log condition checks. A free account includes sign downloads, the on-screen sign register, and one site report download.
Make your site signs freeWhat the AI can and can't detect
OSHA Scan reads a single photo. That makes it fast and easy for anyone on site — but it also means it has real limits. Here's an honest look at both.
What it can catch from a photo
- Caution stands or signs placed at hazards that need a cover or guardrail
- Signs hidden by hoses, carts, or stored material
- Blank, faded, or damaged sign panels
- Visible hazards in the frame with no warning at all
What a photo can't tell it
- Whether the signal word you chose matches your own hazard assessment
- Exact sign colors and size, or whether the design follows ANSI Z535
- Small or distant sign text
- Whether workers have been trained on what each signal word means
OSHA Scan gives an AI-assisted preliminary review from a photo. It does not replace an on-site inspection by a qualified safety professional, and a compliance score is not an official OSHA determination.
AI photo hazard review
Snap a photo of the job site, and the AI categorizes findings against OSHA standards.
Consistent corrective actions & JHA
Each finding includes consistent corrective actions and structured JHA outputs. Check items off as your crew resolves them.
Compliance scoring
Every inspection gets a deterministic 0-100 compliance score derived from hazard severity, so you can track sites at a glance.
A prioritization aid based on recorded findings—not a certification or a complete measure of site safety.
PDF & Excel exports
Generate detailed inspection reports and export data to Excel for record-keeping and stakeholders.
A qualified person must review AI-flagged items before making safety decisions. Do not replace required comprehensive safety walkthroughs with AI reports. Features, limits, and downloads depend on your account’s plan and permissions.
OSHA Scan in Action
See the workflow click into place
Illustrative AI-assisted workflows. Review the findings; they are not a compliance certification.
Always confirmed by a person on site
A scan is a fast first look, not the final word. Before treating this kind of area as safe, a competent person should still confirm:
- Danger signs are used only for immediate hazards, and caution signs for potential ones
- Signs for the same kind of hazard all follow one design
- Each sign names the hazard and the action to take
- Covers, guardrails, and guards are in place wherever a rule requires them — signs are extra
People also ask
What is the difference between DANGER, WARNING, and CAUTION signs?
They rank severity. Under ANSI Z535.2, DANGER marks a hazardous situation that will result in death or serious injury if not avoided, WARNING one that could result in death or serious injury, and CAUTION one that could result in minor or moderate injury. OSHA's general industry rule uses only danger signs (immediate hazards) and caution signs (potential hazards and unsafe practices). Pick the word by asking how bad the outcome is, and how likely, if someone ignores the sign.
What colors are danger, warning, and caution signs?
Under OSHA's 29 CFR 1910.145, danger signs use red, black, and white, and caution signs use a yellow background with a black panel. ANSI Z535.2 uses red for DANGER, orange for WARNING, yellow for CAUTION, and blue for NOTICE, and the construction rule accepts the Z535.2-2011 designs. Separately, 29 CFR 1910.144 reserves red for danger and fire protection equipment and yellow for caution and physical hazards.
Does OSHA recognize WARNING signs?
OSHA's general industry sign rule defines danger, caution, and safety instruction signs — it has no WARNING sign class. WARNING is an ANSI Z535.2 signal word, and the construction rule, 29 CFR 1926.200, accepts the Z535.2-2011 designs that use it. OSHA's tag rule also allows WARNING tags for hazards between caution and danger (1910.145(f)(7)). Whatever format you use, the sign still has to identify the hazard clearly, and workers have to understand it.
Can a caution sign take the place of a cover or guardrail?
No. A sign warns; it doesn't protect. OSHA's walking-working surfaces rule requires holes to be protected by covers or guardrail systems (29 CFR 1910.28(b)(3)), and other rules require machine guards and enclosures for live electrical parts. A caution stand beside an open trench is extra warning at best — the cover or guardrail is what the rule asks for.
Can OSHA Scan check whether I picked the right signal word?
Not directly. OSHA Scan can't reliably read small sign text or know your hazard assessment, so it doesn't rate your choice of words. It does flag visible mismatches — a caution stand at an open hole, a danger label with no message, a sign hidden behind a hose or a cart — with a possibly related standard and a corrective action. It's an AI-assisted second set of eyes and is not affiliated with OSHA.
Reviewed by OSHA Scan Editorial
This content is produced by the OSHA Scan Editorial team and reviewed with AI assistance. It is general safety information, not legal or compliance advice. OSHA Scan is an independent tool and is not affiliated with, endorsed by, or certified by OSHA or the U.S. Department of Labor.
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