Table 4 Summary of studies generating and analysing isocyanates in fire effluents. Summary of the large-scale fire test and bench-scale methods for generating isocyanates and the materials used, as well as sampling methods, temperature, the isocyanates detected and concentration

Boutin et al (2004)

DIN 53436 furnace

Car paint

Impinger

1,2-MP

Sample temperature:473

Oven temperature: 600

ICA, HDI, all linear isocyanates ranging from MIC to n-hexyl isocyanate, alkenyl isocyanates ranging from propylene to octylene isocyanate and structural isomers of these isocyanates

N/A

The most abundant isocyanates detected were MDI, HDI, TDI and IPDI.

Hertzberg et al (2003)

Room test (ISO19705)

Sofa (containing PUR)

Impinger-filter

DBA

N/A

ICA, PHI, MDI, 2,4-TDI and 2,6-TDI

The average isocyanate concentration measured was approximately 0.5 ppm

The highest concentrations were found in the rigid foams, with PIR, an improved form of PUR, giving the highest yield.

In all foams ICA was the main product and was considered the final breakdown product.

The ratio of ICA to TDI was much higher in full- scale experiments in comparison to the combustion of flexible PUR in the cone calorimeter

Cone calorimeter (ISO5660)

Insulation materials

Impinger-filter

DBA

N/A

ICA, MIC

~800-1000 μg m^-3

Glass fibre insulation gave the highest isocyanate concentration of all materials tested.

ICA and MIC were the most abundant isocyanates.

Karlsson (2001)

Urea-based resins and PUR coated sheets

Impinger-filter

DBA

N/A

ICA, MIC

In Bakelite up to 14 % of its weight was emitted as ICA and 0.1 % as MIC

These amounts dependant on temperature and the duration of the heating.

The composition of the released isocyanates differs between coatings.

Blomqvist et al (2003)

PUR mattresses were used a fire source to trigger a sprinkler system, according to IMO resolution A.800

Impinger-filter

DBA

N/A

ICA and smaller amounts of 2,4-TDI and 2,6-TDI

First test: close to 10 ppb. Second test; 50 ppb.

Comparing the potential health hazard between isocyanates and other major fire gases revealed isocyanates as the greatest hazard.

Lönnermark and Blomqvist (2006)

ISO 5659, large-scale

car fires

Impinger-filter

DBA

N/A

ICA, EIC, MIC, PHI, 2,4-TDI, 2,6-TDI, HDI

Total yield of airborne isocyanates: 240 g/kg

Significant amounts of isocyanates were found in the smoke from the vehicle fires

Blomqvist et al. (2007)

Identical setup to BS 7990:2003

PUR mattresses and insulation material, wood

Impinger-filter

DBA

650 °C and 825 °C

ICA, TDI, EIC

PUR mattress:~ 2 mg/g

PUR insulation: :~ 2.5 mg/g

Wood: 0.0035 mg/g

Two different fire scenarios were investigated; well-ventilated and under-ventilated

No significant differences in isocyanate generation were detected for the two fire scenarios

Blomqvist et al. (2014)

ISO/TS 19700

PVC carpet, wood board

Denuder

DBA

350 °C, 650 °C and 825 °C

ICA, MIC, EIC, PHI, MDI

Distribution of isocyanates in gas phase and particle phase were investigated

Mono-isocyanates were found almost exclusively in the gas phase

Only small amounts of di-isocyanates were found

(Fent and Evans (2011))

Vehicle fire

Denuder

DBA impregnated filter

N/A

TDI, MDI, HDI, PHI, MIC, EIC, PIC, IPDI, ICA

5.9-66.8 μg m^-3 TRIG (total reactive isocyanate groups)

Isocyanates were only found in passenger compartment fires and not in engine fires. Isocyanates are present in foam in the passenger compartment and not used in engines.

HSL 2007

Simulated workplace samples (welding of PU painted car parts)

MP impregnated filter

200 °C

TDI, MDI, HDI, PHI, MIC, EIC, PIC, IPDI, ICA, butyl isocyanate, diisopropylphenyl isocyanate, hydrogenated MDI

High levels of ICA (167 mg NCO/m³⁾) and traces of other isocyanates

MP impregnated filter

400 °C

TDI, MDI, HDI, PHI, MIC, EIC, PIC, IPDI, ICA, butyl isocyanate, diisopropylphenyl isocyanate, hydrogenated MDI

High levels of ICA (167 mg NCO/m³⁾) and traces of other isocyanates