Prohibition Signs: Complete Guide for Australian Workplaces

What these signs communicate

A prohibition sign instructs people not to perform a specific action. Typical examples include no smoking, no entry, no mobile phones, no forklifts, no photography and no eating or drinking.

The visual language is consistent: a red circular ring with a diagonal red bar over a black pictogram on a white background. Wording may appear below the symbol, but the pictogram should carry the message without relying on text.

Need them fast? Browse our ready-made and custom options here: Prohibition Safety Signs. We stock common legends and can manufacture site-specific symbols in-house.

Quick order or request a quote now: Prohibition Safety Signs — standard legends ship quickly, and we can turn around site-specific pictograms without outsourcing.

Colour and design conventions

Good prohibition signage follows a simple, highly legible recipe so it is recognised instantly by workers and visitors from diverse backgrounds and literacy levels.

• Red annulus and diagonal bar convey the ban visually.
• Black pictogram on a white field ensures strong contrast and clarity.
• Optional text is typically short, specific and set below the pictogram.
• Avoid decorative elements that reduce legibility or dilute the message.

For AS 1319-style symbols, typical proportions that preserve recognition are: red ring and diagonal bar width approximately 10% of symbol diameter; bar at roughly 45°; pictogram centred with ample white border. We will match your existing site standard if supplied.

Where to place them

Placement should follow your site’s risk assessment so the instruction appears where the decision is made. The sign must be visible before a person undertakes the prohibited action.

• Entry points: No entry, authorisation-only zones, clean rooms and quarantine spaces.
• Hazard areas: No smoking near fuel storage, battery charge bays, paint rooms and gas cylinders.
• Operational zones: No pedestrians in forklift aisles; no mobile phones near sensitive equipment.
• Hygiene areas: No food or drink in production lines, laboratories and clinical spaces.

Use additional directional or location signs if line-of-sight is interrupted or if the approach path is long or complex.

Sizing and legibility (practical AS 1319 guidance)

AS 1319 focuses on clear recognition rather than fixed plate sizes. Use the following rules-of-thumb to ensure the symbol and any wording can be seen in time to act:

• Common plate sizes and indicative viewing distances (stationary or slow approach):
  • 300 x 225 mm: up to ~10 m
  • 450 x 300 mm: up to ~15 m
  • 600 x 450 mm: up to ~22 m
  • 900 x 600 mm: up to ~35 m
• Symbol diameter: aim for 60–70% of sign height so the red ring and bar are dominant.
• Text (if used): uppercase letter height in mm ≈ viewing distance in metres × 5 for critical messages (e.g. 15 m → ~75 mm caps). Go larger for moving traffic (forklifts/vehicles) or low-light areas.
• Mounting height: typically 1.5–1.8 m to the centre of the sign for pedestrian approaches; raise or angle for long approaches or where vehicles are the primary audience.
• Complex environments: if someone has less than 2 seconds of view time (e.g. turning into an aisle), increase size one step up.

Not sure what size you need? Send photos of the location with approximate distances and we’ll confirm a compliant size before production.

Technical sizing guide for moving traffic

For vehicle approaches (forklifts, service utes), increase size to allow at least 2–3 seconds of recognition and decision time.

• Legibility index: plan a minimum of 5–7 mm of uppercase letter height per metre of viewing distance for pedestrians; 8–12 mm/m for vehicle operators.
• Dynamic approach quick-picker:
  • Forklift at 6–8 km/h, 12–15 m view: 600 x 450 mm plate or larger, bold short wording if used.
  • Warehouse vehicle at 10–15 km/h, 20–30 m view: 900 x 600 mm plate recommended; consider reflective film in dim aisles.
  • Outdoor yard at 15–25 km/h, 30–50 m view: 900 x 600 mm minimum; go to 1200 x 900 mm where space permits.
• Reflectivity: in low light, specify retroreflective film to AS/NZS 1906.1 (Class 2 for general use, Class 1W for long approaches/night-time). Note: reflectivity is not required by AS 1319 for most prohibition signs but can materially improve night visibility.
• Contrast: target luminance contrast ratio ≥70% between symbol/text and background.

If you’re upgrading a traffic plan, we can map sizes to each approach based on your layout and typical speeds — simply mark approach distances on a floor plan and send photos.

Material and finish options

Choosing the right substrate affects durability, legibility and total cost of ownership. Consider indoor/outdoor exposure, surface type, expected lifespan and cleaning chemicals.

• Aluminium composite panel (ACP): Rigid, dimensionally stable and suited to long-term outdoor use. Excellent print quality and edge finish after CNC routing.
• Aluminium sheet: Durable metal plate option where impact resistance is critical.
• Corflute: Lightweight corrugated plastic for temporary worksites and short-term projects.
• Self-adhesive vinyl decals: Apply to doors, glass, machinery and smooth walls. Choose removable, permanent or high-tack adhesives to match the surface.
• Laminated vinyl: Adds abrasion and chemical resistance for frequent cleaning or high-traffic areas.
• Engraved lamina (phenolic/laminate tags): For small durable tags on equipment and panels.

Typical service life expectations (indicative, Brisbane SEQ climate): ACP with UV print 5–7 years; ACP with UV print + overlaminate 7–10 years; aluminium plate 7–10 years; laminated vinyl 3–5 years outdoors (longer indoors); corflute 6–18 months. Coastal or high-UV sites may shorten these ranges.

Standard fabrication details we can pre-set for you:

• Corner radii: 5 mm as standard (others on request).
• Fixing holes: 6 mm or 8 mm diameter, typically 15–20 mm in from edges; slotting available for mesh fences.
• Adhesive systems for decals/plates: 3M VHB 5952 tape strips for smooth metal/glass; high-tack acrylics for powder coat and low-energy plastics; optional edge-sealant where moisture is present.
• Overlaminates: 100 μm clear film in gloss or matte; anti-graffiti options for public interfaces.

How we manufacture in-house

At Sign Portal, prohibition signs are produced end-to-end in our approximately 480 m² manufacturing facility with clean, specialised print rooms. Rigid signs are direct UV printed on our Mimaki JFX EX flatbed printers for crisp symbols and durable colour.

Vinyl decals and labels are printed and contour-cut on our Roland VG-640 printer/cutter. ACP and aluminium panels are profiled on our MultiCam SM2412 CNC router for clean edges and accurate rounded corners. Small tags and plates can be laser cut or engraved on our Trotec Speedy 500 or large-format 230 W CO2 laser where suitable.

• Direct-to-substrate UV print for rigid materials reduces seams and delamination risks.
• Contour cutting enables precise circles and symbol silhouettes for window or equipment decals.
• Lamination is available where abrasion, solvents or frequent cleaning are expected.

Process control you can audit: colour-managed workflows with device-linked CMYK profiles; on-press colour checks using a handheld spectrophotometer; adhesion spot checks on metals and ACP using cross-hatch tape tests; and batch traceability on inks, films and substrates. Typical routing tolerance is ±0.5 mm with standard 5 mm corner radii unless specified otherwise.

We can add site asset IDs, QR codes for reordering, grommet holes, VHB tape strips or pre-drilled fixing holes at your requested centres. For decals, we stock permanent and high-tack adhesives and can advise based on surface energy (e.g. powder coat vs glass vs HDPE).

Our QA, equipment and real results

First-party controls you can reference on your procurement files:

• Colour targets: we verify ΔE tolerances on red rings and blacks during each print run using a handheld spectrophotometer and retain swatch cards against your job number for repeatability.
• Adhesion: cross-hatch tape testing on metals/ACP to an internal acceptance criterion before a batch is cleared for dispatch.
• Materials: we stock premium printable films and laminates paired to environment (e.g. high-tack acrylics for powder coat, removable adhesives for glass) and maintain batch/lot traceability.
• Routing and finishing: MultiCam SM2412 CNC cut accuracy typically within ±0.5 mm; deburred edges, standard 5 mm radii unless specified.

Documented outcomes: councils and utilities re-order using our embedded QR codes years later with exact colour consistency; our maintenance clients report improved visibility in dim corridors after upgrading to retroreflective Class 2 film with anti-graffiti overlaminate.

Artwork and file setup

Supplying clean artwork ensures crisp reproduction and consistent safety colours. Where possible, provide vector artwork for the pictogram and shapes.

• Artwork files: Preferred formats are vector-based (AI, PDF, EPS) with outlined fonts.
• Colour mode: Use CMYK builds. If exact colour matching is critical, advise during ordering.
• Line clarity: Avoid overly thin strokes in the pictogram to prevent visual break-up at a distance.
• Margins: Keep adequate white space around the symbol so the red ring and bar remain dominant.
• Text: If used, keep it short and set for legibility at the intended viewing distance.

Installation basics

Installation must keep the sign visible, secure and appropriate to the surface. Consider approach angle, lighting and potential obstructions.

• Fixings for rigid signs: Screws with appropriate wall plugs, rivets to metal, or VHB tape for smooth surfaces.
• Fences and mesh: Use cable ties through pre-drilled holes or grommets.
• Glass and doors: Apply self-adhesive vinyl; clean and degrease before application.
• Curved or textured surfaces: Select a conformable vinyl and suitable adhesive.
• Exterior durability: Use corrosion-resistant fixings in coastal or industrial environments.

Heights and spacing: Mount at 1.6 m to centre for pedestrian areas; cluster related messages but keep at least one sign width of clear space between different categories to preserve recognition. Angle plates toward the approach if they sit along a corridor rather than at a head-on view.

Installer tips from our field notes:

• Surface prep: wash, rinse, then isopropyl alcohol wipe; ensure surface temperature 10–35 °C before applying decals or tapes.
• Torque: avoid over-tightening screws on ACP; use washers on mesh to spread load.
• Glass: wet-apply larger decals for alignment; dry-apply smaller labels with firm squeegee strokes from centre out.

Related sign types explained

Prohibition signs work alongside other categories to create a complete safety communication system. The table below contrasts them with mandatory signs, which tell people what they must do.

Common mistakes and how to avoid them

• Low contrast: Faded reds or greys reduce recognition. Choose substrates and inks suited to UV exposure and consider lamination where needed.
• Too small for distance: Size the symbol for the viewing distance and approach speed. If in doubt, go larger.
• Clutter: Combining too many messages on one plate leads to poor comprehension. Use separate signs if necessary.
• Inconsistent symbols: Mixing styles confuses users. Standardise pictograms site-wide.
• Wrong adhesive: Low-tack vinyl on rough surfaces leads to lift and failure. Match adhesive to the substrate.
• Poor placement: Signs hidden behind open doors or equipment are ineffective. Check views from typical approach paths.

Australian environment considerations

Australian UV, heat, dust and coastal salt can accelerate wear. Select materials and finishes to suit local conditions and cleaning regimes.

• High UV exposure: Direct UV printing onto ACP with a suitable finish provides robust performance. Consider lamination for frequent washing.
• Coastal and industrial sites: Use corrosion-resistant fixings and avoid dissimilar metal corrosion where possible.
• Heat and cold cycles: Adhesive selection matters on glass, powder coat and textured masonry; high-tack or specialty adhesives may be needed.
• Low light: In some locations, reflective films can improve visibility at night or in dim corridors.

Ordering checklist

Clear instructions reduce back-and-forth and speed production. Include the following when requesting a quote or placing an order:

• Message and symbol: Pictogram only or pictogram plus text.
• Substrate and finish: ACP, aluminium, corflute, vinyl decal, lamination if required.
• Mounting method: Screws, rivets, tape, grommets, posts, or decal application.
• Environment: Indoor/outdoor, exposure to chemicals, cleaning and abrasion.
• Quantities and delivery locations: Site names, access details and any deadlines.
• Artwork files: Vector where available; confirm colours and any brand requirements.

Ready when you are — get standard legends or configure customs: Prohibition Safety Signs.

Repair and refurbishment

When a sign is damaged, illegible or detached, replace it immediately. For minor issues, the following repair methods can extend service life safely:

• Graffiti and contamination: For laminated prints, use non-abrasive graffiti removers or isopropyl alcohol. For unlaminated prints, test in an inconspicuous corner first; avoid strong solvents.
• Edge lift on decals: Warm gently with a heat gun and re-squeegee with pressure; apply an edge-sealer where ongoing moisture is expected.
• Scratches and chips on rigid plates: Small chips may be acceptable if the symbol and red bar are unaffected. If the ring/bar/pictogram is compromised, replace the panel.
• Loose fixings: Refit with appropriate corrosion-resistant screws/rivets and oversized washers on mesh. If holes have elongated, shift centres or replace the plate.
• Temporary cover-ups: Do not tape over a prohibition sign. If the control changes, remove or replace the sign to prevent mixed messages.

We supply repair kits on request: matching spare decals, cable ties, stainless fixings, VHB tape strips, alcohol wipes and an instruction sheet tailored to your substrates.

Detailed repair guidance we can include with your order:

• Edge-sealing: apply a thin bead of clear edge-sealer to exposed decal edges in wet areas (typical cure 24 h).
• Rebonding ACP plates: clean substrate, apply new VHB tape strips with 100% coverage near corners and 50% in-field, roll with pressure to activate bond.
• Inspection interval: add signs to monthly housekeeping; for harsh outdoor sites, move to fortnightly quick visual checks.

How Sign Portal helps

We manufacture prohibition signs in-house using two Mimaki JFX EX flatbed UV printers, a MultiCam SM2412 CNC router, Trotec Speedy 500 laser, a large-format 230 W CO2 laser and a Roland VG-640 wide-format printer/cutter. Our 480+ m² facility with clean print rooms supports consistent colour and reliable lead times.

As a Veteran-Owned business with Local Buy credentials, we ship Australia-wide including regional and remote delivery. Repeat ordering is streamlined with customer-specific catalogues and saved artwork, helping multi-site operators keep signage consistent.

First-party results: our internal QC records show stable reds and deep blacks on ACP after prolonged outdoor exposure in SE QLD when using our UV workflow, with routine cleaning and appropriate lamination where required. Councils and utilities use our batch-labelled plates for easy reorders years later. Ask us to add QR reorder codes to your next run.

Maintenance and inspection

Safety signs should be visible, legible and securely fixed at all times. Build them into your routine inspections and housekeeping.

• Cleaning: Use non-abrasive cleaners and soft cloths; avoid harsh solvents on unlaminated prints.
• Fixings: Check for loose screws, lifted vinyl edges and cracked panels; replace as needed.
• Fading or damage: Replace at the first sign of colour loss, cracks or vandalism.
• Site changes: Update messages when processes or layouts change to prevent mixed signals.

Want a one-click reorder path for maintenance teams? We can print a small QR code on the back of each plate linking to your pre-approved item in our system.

Key takeaways

Use prohibition signs wherever a clear “do not” instruction is needed to control risk. Choose materials to match the environment, keep symbols consistent and install for immediate visibility. With in-house UV printing, CNC routing and laser capability, we can produce durable signs across rigid plates and decals, and deliver Australia-wide.

Ready to order or standardise your site set? View our range and request a quote: Prohibition Safety Signs.

Related Sign Portal resources: Prohibition - Do Not Wear Gloves Sign · Prohibition - No Forklifts Sign · Prohibition - Fire Naked Flame Prohibited Sign