Fire-Rated Polycarbonate Sheet: Five Questions That Get a Real Answer

Three vocabularies for the same product

The same flame-retardant PC sheet may be described in three incompatible ways:

These do not convert into one another. A European project wants an EN 13501-1 classification, a Chinese project looks at GB 8624, a North American one at ASTM E84. If a supplier hands you a report saying "flame retardancy: pass", first establish which standard it was issued against.

Five questions to ask

1. Which standard, which class?

Insist on the standard number and class — "EN 13501-1 B-s1,d0" or "GB 8624 B1". Phrases such as "flame retardant" or "self-extinguishing" cannot be used for approval.

2. Which thickness does the report cover?

Fire performance is strongly thickness-dependent. A 4 mm report does not cover 10 mm sheet, and vice versa. Match the report to the thickness you are buying.

3. Same structure and colour?

Multiwall and solid behave differently in fire; within one structure, dark and light colours absorb heat differently and can shift results. Have the report state structure and colour, or confirm the covered product family in writing.

4. Test date and batch?

Formulations change. A report older than three to five years warrants a recent retest, and you should confirm the tested sample came from the current production formulation.

5. Does installation affect performance?

The most overlooked point. Sealants, adjoining materials and perimeter fire stopping all affect the performance of the assembly. A compliant sheet does not guarantee a compliant construction.

Two things that matter more than the class letter

1. Smoke.

Smoke, not flame, is the main killer in a fire. The European s1/s2/s3 suffixes grade smoke production — two sheets can both be class B while offering very different escape conditions at s1 versus s3. Read the s classification before the B.

2. Droplets.

PC softens and drips when heated. The d0/d1/d2 suffixes describe flaming droplets. d0 means none, which matters wherever people or combustible goods sit below — the reason skylights, facades and noise barriers usually specify d0.

What each application cares about

• Industrial roof lights: flame spread and droplets dominate; roof lights crossing fire compartment boundaries are often restricted and must follow local fire code.

• Public building skylights: smoke toxicity and droplets are the priorities; higher s and d classifications are typically required.

• Transport noise barriers: sections connected to tunnels or stations carry stricter requirements than open-road sections.

• Greenhouses: generally lower requirements, though assemblies attached to occupied buildings still follow code.

Where SINHAI stands

We can supply third-party flame-retardancy test reports for our multiwall and solid sheets by thickness, matching the board type. We do not pick a class on the customer's behalf — the class is set by national code, fire authority review and insurance terms. The workable sequence is: you give us the requirement (standard, target class, thickness), we confirm which product matches and send the report number and date for verification.

If all you have is "flame-retardant sheet required", we can provide reports for our standard FR grades for your designer to assess.

FAQ

Does adding flame retardants reduce light transmission?

Usually slightly, and the sheet may carry a faint tint (towards opal or pale yellow). That is why many projects use FR sheet only in specific areas and standard sheet elsewhere. Put the transmission requirement into the specification alongside the fire requirement.

How much more does FR sheet cost?

It depends on the retardant system and the class required. Higher class and additional certification raise cost. Ask for a price by thickness — negotiating on "roughly what percentage more" is where buyers get caught out.

Can an English-language report be used for a European project?

Language is not the issue; the standard is. Confirm the report comes from an accredited laboratory, cites the currently valid version of the standard, and covers your product model. With those three verified, language and notarisation become a formality.