Last year, a project in Chengdu, the client temporarily notified the procurement team that all carpets needed to provide B1-level testing reports for fire inspection. The supplier responded that ”some testing reports are B1 level, but the current batch has not yet been tested.” As a result, the project was delayed by two weeks. Calculate the daily comprehensive cost of hotel preparation—at least hundreds of thousands.

I have seen this kind of scenario more than ten times in recent years. To be honest, most hotel procurement teams” understanding of flame retardant standards stops at ”having this thing is enough," and few truly understand:How exactly is B1 level tested? Can different testing standards be mutually recognized? Is it enough to just have the report?

---

1. What exactly does B1 flame retardant level test?

First, clarify a concept. The domestic hotel carpet flame retardant requirements are based on GB 8624-2012 "Classification of the Combustibility of Building Materials and Products", which divides combustion performance into four levels:

Level	Name	Applicable scope for hotels
A Level	Non-combustible materials	Evacuation stairs, fire elevator lobbies, etc.
B1 Level	Difficult-to-burn materials	Guest rooms, corridors, banquet halls, conference rooms
B2 Level	Combustible materials	Generally not suitable for hotel public areas
B3 Level	Flammable Materials	Prohibited from Use

Most people understand ”B1 Level” as a composite indicator. According to GB 8624, B1 level requires meeting the following conditions:

1️⃣ Critical Heat Flux (CHF) ≥ 4.5 kW/m²— In simple terms, it means the material can extinguish itself after the fire source is removed and does not burn continuously

2️⃣ Smoke Toxicity Level not lower than T1— The smoke toxicity produced by burning carpets must not exceed standards

3️⃣ Burning drips cannot ignite filter paper— Melted dripping materials cannot become a new fire source

What is often overlooked here is item 2. Many carpet materials are inherently flame-retardant, but after adding flame retardants, the smoke toxicity during combustion exceeds standards, and they still fail B1. We tested a batch of samples with SGS; initial flame retardancy all passed, but all smoke toxicity alarms triggered—flame retardants themselves become the source of the problem.

---

Second, B1 level testing, hiding several ”traps”

Trap one: Testing standards do not match the applicable scenarios

The most common flame-retardant testing methods for domestic hotel projects:

Testing standards	Test Content	Applicable Scenarios	Relationship with Level B1
GB/T 11785-2005	Radiant Heat Source Method (Critical Radiant Flux)	Dedicated for Flooring Materials	Mandatory Item for Level B1
GB/T 8626-2007	Ignition and Combustion Performance (30s/15s)	General Building Materials	Auxiliary Indicator for Level B1
GB/T 17658-1999	Carpet Combustion Performance Test	Vertical Combustion of Carpet	Additional Requirements for Some Items
ASTM E648	Critical Radiant Flux (American Standard)	International Brand Hotels	Method Cited by NFPA 101

The biggest pitfall: Some suppliers provide test reports for ASTM E648 Class I, which only indicate compliance with the US NFPA 101 standard, and do not have a direct correlation with GB 8624 B1 grade. International brand hotels operating domestically still rely on national standard reports for fire inspection.

Pit two: The sample sent for testing and the supplied product are two different things.

This is perhaps the most common issue in the industry. When sending samples for testing, a batch of material with special flame-retardant formulations and processes is used. During mass production, to reduce costs, it is replaced with ordinary yarns or low-weight backing fabrics. The test report is genuine, and the product is genuine — but they are not the same thing.

Last year, for an Intercontinental project in East China, we proactively requested athird-party batch sampling and testing, and sent it for re-testing at SGS. It’s not that we don’t trust our process, but from yarn input to finished product, any fluctuation in any process could affect the flame-retardant performance. The final report showed all qualified, the customer was assured, and we felt at ease.

💡 Tips: Adding a clause in procurement terms for ”bulk batch sampling and re-testing” — the cost is usually 3,000-5,000 yuan per test, which is negligible compared to the value of the entire carpet batch, but it can close the risk gap of 99%.

---

3. Differences in flame retardancy of carpets with different processes

Not all carpets have the same flame-retardant solutions. Different materials and processes have completely different underlying logic for flame retardancy:

Nylon 66 carpets (mainly tufting process):

• Nylon’s oxygen index (LOI) is 20-22, classifying it as a combustible material
• Flame retardants must be added, with mainstream solutions beingPhosphorus-based flame retardants + anti-drip agents
• The cost of flame-retardant treatment per square meter increases by approximately 8-15 yuan
• Note: Flame retardants can affect color fastness, especially in dark colors

Wool carpets:

• Wool’s natural oxygen index (LOI) is 25-28, with natural flame-retardant properties superior to synthetic fibers
• However, burning wool produces smoke, and the toxicity of the smoke needs to be closely monitored
• Pure wool carpets mostly meet B1 grade in GB 8624 testing, but auxiliary flame retardant treatment is required when the fleece density is less than **1000g/㎡**

Handmade gun刺 carpets:

• Cotton backing is a weak link in flame retardancy
• Our factory's approach is to useFlame-retardant treated cotton backing + flame-retardant latex, double protection
• In 2023, the handmade gun刺 carpets supplied for a Marriott project in Chongqing were tested by TÜV and the critical heat radiation flux reached6.8 kW/m², far exceeding the B1 level threshold

---

4. What else does procurement need to do after obtaining the B1 report?

Step 1: Confirm the product scope covered by the report

The test report will specify the product model, batch number, and specifications. Verify whether it matches the SKU you purchased. Some suppliers provide a report covering over ten models, but in reality, only one was tested.

Step 2: Confirm the qualification of the testing organization

Domestic recognized flame-retardant testing organizations:

• National Fireproof Building Material Quality Supervision and Inspection Center (Dujiangyan, Sichuan)
• National Building Fireproof Product Safety Quality Supervision and Inspection Center (Beijing)
• Third-party: SGS, Intertek, TÜV domestic laboratories
• The test reports from these organizations are all recognized for fire safety acceptance

Step 3: Confirm the validity period of the report

Many procurement staff do not know — testing reports usually do not have a strict validity period, but industry practice suggeststhat reports for the same product within 2 yearscan be trusted. If your product's process, raw materials, or formulation have not changed, you can continue to use the same report. However, if there are any changes, re-testing is required.

Step Four: Prepare an ”Emergency Plan”

Our suggestion to the customer: Reserve spare blankets for each project amounting to **3%-5%**, in the same batch and process as the main batch. In case sampling and testing are required during acceptance of a certain area, it will not affect the overall progress.

---

Section V: Trends in Flame Retardant Standards for 2026-2027

The 'Technical Specification for Fire Performance Evaluation of Building Interior Materials' (Draft for Comments) released by the China Academy of Building Research at the end of 2025 sent a signal:The requirements for smoke toxicity levels are becoming stricter. The current standard level T1 is the entry threshold; the new regulation may require key areas to reach T0 level.

What does this mean? It directly impacts the carpet manufacturing side—flame retardant formulations need to be re-optimized. Simply increasing the amount of flame retardant to meet standards is no longer feasible, as higher flame retardant use may increase smoke toxicity. The solution is: start from the raw fiber material, select base fibers with higher oxygen index, and reduce reliance on flame retardants.

Esen Carpet's R&D team has been working on this since 2024—collaborating with two domestic chemical fiber factories to developModified Nylon 66 yarnsthat increase the base oxygen index to24%and reduce flame retardant usage by approximately35%while maintaining smoke toxicity at T0 level.

---

Returning to the earlier case of acceptance delay

The core issue is not whether there is a report, but whether the procurement party manages flame retardancy as a ”systematic indicator.” A report is just the result; if any link in the chain—from raw materials to process, quality control, and re-inspection—is disconnected, that paper is just a formality.

If you are preparing to purchase hotel carpets, here are some suggestions:

• Confirm whether you need GB 8624 B1 level or if there are other project-specific requirements
• After obtaining the test report, first check the product batch, testing method, and whether all SKUs are covered
• Include clauses for bulk sampling and re-testing in the procurement contract
• Confirm with the supplier the impact of the flame retardant scheme on color fastness and texture

Our team has served over a hundred hotel projects. The experience with flame retardancy is: the earlier the standard communication, the smoother the later acceptance process. If you need specific testing plans or report templates for reference, you can directly communicate with the technical team of Yisen Carpet—after all, product safety and compliance are the bottom line for both manufacturers and purchasers.

---

【Note】

• Data sources in the text: GB 8624-2012 'Classification of Building Materials and Products' for Combustion Performance, GB/T 11785-2005 'Determination of Critical Heat Flux of Flooring Materials', China Academy of Building Research 'Technical Regulations for Fire Performance Evaluation of Interior Building Materials' (Draft for Comments 2025), Yisen Carpet Laboratory's measured data.
• The reference price for testing fees is based on SGS East China Laboratory's 2025 quotation.
• Case data has been anonymized.