What is ASTP 5007?

ASTP 5007 is the Mine Safety and Health Administration (MSHA) standard for flame resistance. It confirms suitability for hazardous underground mining environments.

What does ASTP 5007 evaluate?

It determines flame propagation properties of components used in the Firesleeve construction when exposed to an ignition source under controlled airflow.

• How easily the Firesleeve catches fire
• Whether the Firesleeve stops burning within 15 seconds once the test flame is removed
• Whether it contributes to fire spread in restricted, high-risk mine environments

What does “Accepted by MSHA” mean?

“Accepted” is the formal status granted by MSHA indicating the product has met technical requirements of 30 CFR Part 18 for accessories used in gassy mines and tunnels.

Products not accepted may pose a fire safety hazard.

How did our Firesleeve perform?

Tested to ASTP 5007, our Firesleeve met the criteria and was awarded MSHA “Accepted” status.

Does MSHA have a formal product list?

Yes — MSHA maintains a list of accepted flame-resistant equipment/products. Our Firesleeve was accepted in October 2024 (Acceptance No. IC-413/01).

What does “Tested to EN 45545-2:2020” mean?

EN 45545-2:2020 is widely regarded as the “gold standard” for fire safety in the European railway industry. It helps ensure materials won’t endanger passengers through fire, smoke or toxic fumes in trains and tunnels.

The three parts of EN 45545-2:2020

• Flame spread — how fast the material burns (via EN ISO 4589-2)
• Smoke density — how much smoke is produced (via ISO 5659-2)
• Toxicity — whether emitted smoke contains lethal gases (via BS EN 17084:2018)

Why is EN 45545-2:2020 important?

It harmonises safety rules across Europe. An HL3 rating under R22 indicates suitability for use in virtually any railway application globally.

How did our Firesleeve perform?

Our Firesleeve complies with requirements R22 & R23 for HL1, HL2 and HL3. This supports use across a wide range of rail applications worldwide.

What does “Tested to BS EN ISO 4589-2” mean?

It means our Firesleeve underwent an Oxygen Index (OI) test at ambient temperature to determine flammability. Materials with an OI below 21% burn easily in air. Values above 26% typically indicate self-extinguishing behaviour and high flame resistance.

How is the test conducted?

• Small sample placed vertically inside a transparent test chimney
• Precise nitrogen/oxygen mixture flows upward through the chimney
• Top of the specimen is ignited and burn behaviour is measured at varying oxygen levels

Why is this important?

High-risk industries (rail, underground transport) often specify minimum Oxygen Index levels to ensure materials are self-extinguishing in standard air.

Interpretation of results

Oxygen Index (OI)	General flammability rating
< 21%	Highly flammable (burns easily in normal air)
21% – 26%	Moderately flame retardant
> 26%	Self-extinguishing / High flame resistance

How did our Firesleeve perform?

Our Firesleeve shows an Oxygen Index of 32.5% ± 0.54% — deemed a GOOD PASS and will not support combustion.

What does “Tested to ISO 5659:2026” mean?

It means our Firesleeve has been evaluated for how much smoke it produces when exposed to heat/fire. Higher optical density indicates thicker smoke, reducing visibility and safe evacuation in emergencies.

How is the test conducted?

This is a single-chamber test where smoke is collected inside a sealed cabinet to simulate enclosed spaces such as railway carriages and tunnels.

• Small flat sample placed horizontally in the chamber
• Exposed to thermal radiation (25 kW/m²)
• Modes include non-flaming (smouldering) and flaming (pilot flame)

Why is ISO 5659 important?

It’s critical for materials used in enclosed public transport systems where escape is difficult. In rail systems, ISO 5659 underpins smoke requirements within EN 45545-2.

How did our Firesleeve perform?

Our Firesleeve showed a Ds(max) value of 95 at 10 minutes and 96 at 20 minutes — deemed a GOOD PASS for HL1, HL2 and also HL3 zones.

What does “Tested to BS EN 17084” mean?

It means our Firesleeve has been evaluated for smoke toxicity — focusing on the chemical danger of fumes produced when materials burn (European railway industry).

Which toxic gases are considered?

• Carbon Monoxide (CO), Carbon Dioxide (CO2)
• Hydrogen Bromide (HBr), Hydrogen Chloride (HCl)
• Hydrogen Cyanide (HCN), Hydrogen Fluoride (HF)
• Nitrogen Oxides (NOx), Sulphur Dioxide (SO2)

How is the test conducted?

Over a 40-minute test duration, gases are measured using a combination of infra-red analysis, chemiluminescence, gas sampling bags, bubbling through aqueous media and ion chromatography.

Why is BS EN 17084 important?

In rail/underground fires, smoke inhalation causes more fatalities than flames. This test helps ensure materials won’t release a lethal mix of gases that prevents safe evacuation.

How did our Firesleeve perform?

The key output is CITNLP. For HL3 applications, the value must be very low (≤ 0.90). Our Firesleeve achieved CITNLP = 0.03 — a GOOD PASS for HL3 zones.

What does a V-0 rating mean?

A V-0 rating under UL 94 / IEC 60695-11-10 signifies the silicone has passed the most stringent level of vertical flammability testing and demonstrates excellent self-extinguishing behaviour.

V-0 characteristics (high-level)

• Self-extinguishing — stops burning within 10 seconds after each flame application
• No flaming drips — does not ignite a cotton indicator placed below
• Total burn time — across 5 specimens (10 flame applications), total flaming time ≤ 50 seconds
• Afterglow restriction — glowing combustion does not persist > 30 seconds after removing flame
• Flame containment — does not burn up to holding clamp

Why is V-0 important?

It is a widely recognised benchmark for industries where fire risk is high (public transport, mining, electronics, automotive, aerospace). Many standards and codes require V-0 materials to access specific markets.

Classification criteria (summary)

Condition	V-0	V-1	V-2
Afterflame time for each specimen (T1 or T2)	≤ 10 s	≤ 30 s	≤ 30 s
Total afterflame time for 5 specimens (T1 + T2)	≤ 50 s	≤ 250 s	≤ 250 s
Afterflame + afterglow after second flame (T2 + T3)	≤ 30 s	≤ 60 s	≤ 60 s
Afterflame/afterglow up to holding clamp	NO	NO	NO
Cotton indicator ignited by flaming particles/drops	NO	NO	YES

How did our Firesleeve perform?

Our Firesleeve silicone has been rated V-0, confirming high flame-retardant and self-extinguishing characteristics where V-0 materials are required.