Here’s a concise list of widely used, top‑rated fireproofing coatings and systems for protecting structural steel — grouped by type (what they are best at) with example, market‑leading products/manufacturers and short notes on when to choose them.

Important: final product choice must be based on the required fire‑resistance rating, exposure (interior/exterior, humidity, abrasion), code/UL/ICC listings for the specific assembly, and approval/skill of the applicator.

1. Cementitious spray‑applied fire resistive materials (SFRMs)

• Best for: economical protection of concealed steel and decks where thickness (and weight) is acceptable; widely used for 1–4 hour ratings.
• Top products / makers: Monokote (GCP Applied Technologies) — Z‑106 series, MK series; CAFCO / Isolatek (e.g., CAFCO 304, CAFCO 400 / FENDOLITE M‑II). These are proven, UL/ASTM‑tested SFRMs used on commercial and industrial projects. (gcpat.com)

2. Intumescent coatings (thin‑film IFRMs)

• Best for: architecturally exposed steel (aesthetics), where slender coatings are required to meet the same fire rating as thick SFRM; suitable for interior or protected exterior use when paired with approved topcoats.
• Top products / makers: Nullifire (Tremco CPG) SC900 series — SC902 (fast‑track, one‑coat, up to 120 min loadings); Carboline intumescent and other two‑pack or waterborne intumescents; Fireshield intumescent systems. Intumescents are available in single‑ and two‑component systems and are specified per UL/EN loading tables. (Nullifire.com)

3. High‑density / trowelable cementitious (exterior / abusive environments)

• Best for: exterior steel, parking garages, heavy‑traffic or mechanically exposed steel where abrasion/weather resistance is needed.
• Top products / makers: CAFCO FENDOLITE / Isolatek Type M‑II and Monokote Z‑156 (high density offerings). These are designed for superior thermal performance and durability in harsh exposures. (Isolatek.com)

4. Factory‑applied shop intumescents (off‑site systems)

• Best for: controlled shop application for large fabrications (reduces field work and cure/weather concerns) — many intumescent manufacturers offer shop systems (e.g., Nullifire SC901 for shop application variants).
• Use when logistics or site conditions make on‑site application difficult; check manufacturer shop‑approval scheme and applicator qualifications. (tremcocpg-asiapacific.com)

5. Specialty systems (hydrocarbon fires, offshore/industrial)

• Best for: petrochemical, offshore, or tunnel applications where hydrocarbon fire exposures or corrosion are concerns.
• Notable brand series historically used: Chartek (AkzoNobel) and specialized Carboline industrial systems — specify per project hazard and test standard (hydrocarbon vs. cellulosic). (See manufacturer product literature for the exact Chartek / industrial product matching your hazard.) (Carboline.com)

How to pick between them (practical checklist)

• Required fire‑resistance duration (e.g., 60, 120, 180, 240 minutes) and whether rating is for column/beam/deck assembly. Select a product with tested loading tables for those elements. (Manufacturer UL/EN/ICC listings show required thicknesses/loadings.) (gcpat.com)
• Exposure conditions: exterior, pools/chemicals, humidity, abrasion — use high‑density cementitious or specially top‑coated intumescent for harsh conditions. (Isolatek.com)
• Aesthetics & weight: exposed architectural steel → intumescent (thin film). If weight and thickness are less of a concern → SFRM. (Nullifire.com)
• Application method and schedule: SFRM requires spray crews and drying time; some modern intumescents (fast‑track) allow single‑coat, quick cure. Verify ambient temp/humidity limits. (tremco.com.au)
• Code/standards: verify UL‑classified or ASTM/EN/ICC‑ES designs for the exact assembly (ASTM E119 / UL 263, EN/BS standards, ICC‑ES reports). Manufacturer data sheets and UL/ICC design directories are essential. (gcpat.com)
• Applicator qualifications: many manufacturers require certified/approved applicators for warranty and to maintain UL listings (especially for intumescent and fast‑track systems). (firestoppingshop.com)

Short list of commonly specified / market‑leading names (summary)

• Monokote (GCP Applied Technologies) — cementitious SFRM (Z‑106, MK series). (gcpat.com)
• CAFCO / Isolatek (FENDOLITE, Blaze‑Shield, CAFCO 304/400) — commercial and high‑density SFRMs. (Isolatek.com)
• Nullifire (Tremco CPG) SC800/SC900 series — modern intumescent systems (SC902 = fast‑track on‑site up to 120 min). (Nullifire.com)
• Carboline — industrial/commercial intumescent and cementitious products (Pyrocrete, etc.). (Carboline.com)
• Fireshield (Fireshield® intumescents) — waterborne and solvent systems for 30–180+ min ratings (architectural & structural). (fireshieldcoatings.com)

Next steps I recommend (practical)

• Identify the required FRR (minutes) for each steel member and the exposure class (interior/exterior, corrosivity, abrasion).
• Pull the UL/ICC/EN/BS design numbers from the manufacturer’s datasheets for those member types and ratings (manufacturer websites list loading/thickness tables). (gcpat.com)
• Use a manufacturer‑approved applicator and verify third‑party inspection/testing (thickness/density/bond checks) per the spec.
• If you want, tell me the project type (interior/exterior, target FRR, exposure) and I’ll shortlist 2–3 product systems and cite the exact UL/ICC listings and typical thicknesses for your case.

If you want product data sheets, UL/ICC design numbers, or typical thickness/load tables for any of the items above, I can fetch and paste those specific manufacturer listings and citations.