The Explanation LabAll 20 lessons

16 STRUCTURE · Information shaped like the task

Warn before the action.

You will learn how to write a safety message people read in time, using the structure and signal words of ANSI Z535. It takes 3 minutes.

Follow along

Here are the steps for cleaning a table saw blade. Read them in order, as if you were doing them.

EXAMPLE PROCEDURE · BEFORE

  1. Remove the blade guard.
  2. Clean the blade with a brush.
  3. Note: unplug the saw first. The blade can start unexpectedly.

The warning is the last line. By the time you read it, your hand is on the blade.

The information is all there. It's in the wrong place.

Watch the clip

The clip runs the same three steps at doing speed, then moves the warning. Watch where it lands.

28 seconds · lesson 16 of 20 from the full video

The name for it

THE NAME FOR IT

ANSI Z535 safety communication

ANSI Z535 · US standards for safety signs, labels and manual messages

A safety message names the hazard, the consequence and how to avoid it, and it comes before the step it protects.

Put it first

EXAMPLE PROCEDURE · AFTER

!WARNING
HAZARD
The blade can start unexpectedly.
CONSEQUENCE
Contact with the blade can cause serious cuts.
AVOIDANCE
Unplug the saw before you touch the blade or guard.
  1. Unplug the saw.
  2. Remove the blade guard.
  3. Clean the blade with a brush.

The warning now comes before the step it protects, and it answers three questions:

  1. Hazard. What can hurt you? The blade can start unexpectedly.
  2. Consequence. What happens if it does? Serious cuts.
  3. Avoidance. What do you do about it? Unplug the saw first.

Then the procedure starts with the avoidance step itself. The reader does the safe thing before they can do the dangerous one.

Pick the right signal word

The signal word tells the reader how bad it can get. Each one has a fixed meaning and color:

Signal wordUse it when the hazard
DANGERWill cause death or serious injury
WARNINGCould cause death or serious injury
CAUTIONCould cause minor or moderate injury
NOTICEProperty damage, not injury

Use the lowest word that's true. If everything is DANGER, nothing is.

TAKEAWAY

A warning must arrive
before the decision
it governs.

Add safety messages to your own procedure

  1. Read your procedure as if you were doing it. Mark each step where someone could get hurt or break something.
  2. For each mark, write the hazard, the consequence and how to avoid it.
  3. Pick the signal word from the table above.
  4. Put the message directly before the step it protects, never after.
  5. If avoiding the hazard is an action, make it a numbered step too.

The next step uses an agent. It comes with a hazard of its own, so here's the message, before the step:

NOTICE
HAZARD
Agents can drop, round or change numbers when they rewrite text.
CONSEQUENCE
A wrong value in a published procedure can damage equipment or mislead readers.
AVOIDANCE
Before you publish, check every number in the result against the original.
  1. Ask your agent to do steps 1 to 5 for you with this prompt:
PROMPT
Review the procedure below for safety messages, following the ANSI Z535 approach.
1. Find every step where someone could be injured or something could be damaged.
2. For each, write a message with: a signal word (DANGER, WARNING, CAUTION or NOTICE, chosen by severity),
   the hazard, the consequence, and how to avoid it.
3. Place each message directly before the step it protects. Never after.
4. If avoiding the hazard is an action, add it as its own numbered step.
Keep every number and setting from the original exactly as written.

Procedure:
[paste here]

What good output looks like: messages that sit before their steps, signal words that match the severity, and every number from the original unchanged. (That's what the NOTICE above told you to check.)

Sources