Can I use ANSI Z535 signs instead of the old OSHA-style signs?

Generally yes, for the editions OSHA references. OSHA's 2013 signage rule, effective September 11, 2013, added ANSI Z535.1-2006(R2011), Z535.2-2011 and Z535.5-2011 as options alongside the 1967 and 1968 ANSI standards, and the Federal Register notice says the change lets employers update signs to the newer standards without violating OSHA's requirements. In general industry, 1910.145 itself still defines only danger, caution and safety instruction sign classes, so read the section that applies to you.

Do I have to replace my old signs?

Not because of the 2013 update. OSHA said employers would not have to update their signage as a result of that rule. Signs still need to be replaced when they no longer do their job, and 1910.145(a)(2) says new signs and replacements must follow the section's specifications.

Does OSHA set a minimum sign size or letter height?

Not for general industry signs in 1910.145. The section's one distance rule is for tags: the signal word must be readable from at least five feet, or farther if the hazard warrants it. ANSI Z535 gives a method for sizing letters by viewing distance.

Does OSHA approve safety sign products?

No. OSHA does not run an approval or listing program for signs. Whether a sign is acceptable depends on how it is designed, worded, placed and used in your workplace, so treat any claim that a product carries OSHA's approval with caution.

Do the 1910.145 tag rules apply on construction sites?

No. Paragraph (f) says it does not apply to construction or agriculture. Construction signs and tags fall under 29 CFR 1926.200, which references ANSI Z35.1-1968 or Z535.2-2011 for signs and Z35.2-1968 or Z535.5-2011 for tags.

Do signs have to be in English?

Not as such: 1910.145 does not name a language. For tags it says the signal word and major message must be understandable to all employees who may be exposed, so a workforce that reads another language may need bilingual tags; the same reasoning is commonly applied to signs.

What color should a WARNING tag be?

OSHA recommends orange, or predominantly orange, with lettering or symbols in a contrasting color. Appendix A to 1910.145(f) gives that as a recommendation, not a mandate; it also recommends red for DANGER, yellow for CAUTION and fluorescent orange or orange-red for BIOHAZARD.

OSHA Safety Sign Requirements (29 CFR 1910.145)

29 CFR 1910.145, "Specifications for accident prevention signs and tags", is OSHA's main general industry rule on what safety signs and tags look like and how they are used. It is short and, in places, dated, and it is often misread. This guide walks through what it actually says, what changed in 2013, and what it leaves to employers and to the ANSI standards. It covers general industry; construction has its own rule, 29 CFR 1926.200.

What 1910.145 covers

The section applies to signs and symbols meant to indicate, and as far as possible define, specific hazards that could lead to injury to workers or the public, or to property damage. It covers all safety signs except those for streets, highways and railroads, and it does not apply to plant bulletin boards or safety posters. Paragraph (a)(2) says all new signs and replacements of old signs must follow its specifications.

Sign classes and colors

Paragraph (c) sorts signs by use, and paragraph (d) sets their design:

Sign class	When 1910.145(c) says to use it	Colors in 1910.145(d)
Danger signs	Where there is immediate danger and special precautions are needed; employees must be taught this meaning	Red, black and white
Caution signs	Only to warn against potential hazards or to caution against unsafe practices	Yellow background; black panel with yellow letters; black letters on the yellow background
Safety instruction signs	Where general instructions and suggestions about safety measures are needed	White background; green panel with white letters; black letters on the white background

The colors must match the opaque glossy samples in Table 1 of ANSI Z53.1-1967 or Table 1 of ANSI Z535.1-2006(R2011). The section also covers biological hazard signs and the slow-moving vehicle emblem. A separate section, 1910.144, sets the basic safety color code (red for danger, stop and fire protection equipment; yellow for caution and physical hazards such as tripping and "caught in between").

Two general requirements apply to every sign:

Physical design (d)(1): rounded or blunt corners, no sharp edges, burrs, splinters or other sharp projections, and bolt heads or fasteners placed so they are not a hazard.
Wording (e)(2): easy to read and concise, with enough information to be understood, a positive rather than negative suggestion, and accurate in fact.

Accident prevention tags: 1910.145(f)

Tags are temporary devices, usually card, paper, plastic or similar material, used to identify a hazardous condition. Paragraph (f) applies to tags used for hazards that are out of the ordinary, unexpected or not readily apparent, and to tags other OSHA standards require. It does not apply to construction or agriculture. Its main rules:

Every required tag has a signal word (DANGER, CAUTION, or BIOLOGICAL HAZARD, BIOHAZARD or the biohazard symbol) and a major message that states the specific hazard or instruction, such as "Do Not Start" or "High Voltage".
The major message can be text, a pictograph, or both.
The signal word must be readable from at least five feet (1.52 m), or farther where the hazard warrants.
The signal word and message must be understandable to all employees who may be exposed, and employees must be told what each tag means.
Tags must be attached as close as safely possible to the hazard by a positive means, such as string, wire or adhesive, that prevents loss or unintended removal.
DANGER tags are only for immediate hazards that threaten death or serious injury; CAUTION tags are only for non-immediate or potential hazards with a lesser threat. WARNING tags may be used for a level in between.
Tags stay in place until the hazard is removed or the hazardous operation is finished. They are not needed where signs, guarding or other positive protection are in use.

Appendix A to paragraph (f) recommends, but does not require, red for DANGER, yellow for CAUTION, orange for WARNING and fluorescent orange or orange-red for BIOHAZARD tags. Lockout/tagout tags have additional rules in 1910.147, including durability in the expected environment, standardized print and format within the facility, and an attachment means with an unlocking strength of no less than 50 pounds.

The 2013 update and ANSI Z535

On June 13, 2013, OSHA published a direct final rule, "Updating OSHA Standards Based on National Consensus Standards; Signage" (78 FR 35559). It took effect on September 11, 2013, which OSHA confirmed in a notice on November 6, 2013 (78 FR 66642). The rule added references to ANSI Z535.1-2006(R2011) (safety colors), Z535.2-2011 (environmental and facility safety signs) and Z535.5-2011 (safety tags and barricade tapes) to OSHA's signage provisions, while keeping the existing references to ANSI Z53.1-1967, Z35.1-1968 and Z35.2-1968. OSHA's stated purpose was to give employers the option of following either the older or the updated standards.

How that played out by section:

1910.145 (general industry): the color requirements for danger, caution and safety instruction signs now accept Table 1 of Z535.1-2006(R2011) as well as Z53.1-1967.
1926.200 (construction): danger and caution signs may follow figures in Z35.1-1968 or Z535.2-2011, tags may follow Z35.2-1968 or Z535.5-2011, and those standards' additional rules apply.
Other sections: 1910.97 (nonionizing radiation) and 1910.261 (pulp, paper and paperboard mills) gained the same newer references.

The Federal Register notice explains that, before the update, employers who used newer ANSI-format signs could receive de minimis notices for not following the older standards, and that the change lets them adopt the newer standards without violating OSHA's requirements. Note the editions: OSHA incorporated the 2011 versions. Later revisions of the Z535 series exist, but they are not the editions incorporated by reference in 29 CFR 1910.6.

What OSHA does not specify

Sign size and letter height for general industry signs. Only tags have a distance rule.
Materials. 1910.145 asks for safe edges and corners, not a particular stock. 1910.147 does require lockout tags to withstand their environment.
Which hazards need a sign. That comes from other standards and from your own hazard assessment. For example, 1910.146 requires employers to inform employees of permit-required confined spaces by posting danger signs or another equally effective means, and its note gives "DANGER: PERMIT-REQUIRED CONFINED SPACE, DO NOT ENTER" as acceptable wording.
WARNING and NOTICE signs. 1910.145(c) does not define them; they come from ANSI Z535.2.
Symbols. Pictographs are allowed on tags, but OSHA does not prescribe a symbol set.
Product approval. OSHA does not approve or list sign products.

Many states run their own OSHA State Plans, which must be at least as effective as federal OSHA but can have standards that differ in detail. Check your state's rules if you operate in a State Plan state.

Buying signs and tags for an OSHA workplace

Decide the hazard, signal word and wording first, then choose a format: the classic OSHA-style header or an ANSI Z535-format layout. Browse OSHA-format safety signs,accident prevention signs,accident prevention tags andlockout/tagout tags, or send your own wording through thequote form. We print what you specify and approve on the proof; deciding whether a sign is right for your workplace remains your call.