Emergency Response

Mini Safety Data Sheets could be used by First Responders to prepare them for the potential hazards they may encounter when entering or isolating a release site.

Buncefield Tank 912
(image source https://www.hse.gov.uk/research/rrpdf/rr718.pdf)

Cards use the criteria in NFPA 704Standard System for the Identification of the Hazards of Materials for Emergency Response“,

NFPA 704 Diamond

Images and Environmental impact scores are derived from the UN GHSGlobally Harmonized System of Classification and Labeling of Chemicals


The material hazards are similar to the Chemical Safety cards (mini SDS):

Click for Chemical Safety cards

These are summarised as follows:

0No additional health hazardsWill not burn under typical fire conditionsNormally stableNo Special hazardsNo significant harm
1Can cause significant irritationMust be preheated before ignition can occurCan become unstable at elevated conditions1 Special HazardPotentially Harmful (H413)
2Can cause temporary incapacitation or residual injuryMust be exposed to relatively high temperatures before ignitionViolent chemical change at elevated conditions2 Special HazardsHarmful (H402 or H412)
3Can cause serious or permanent injuryCan be ignited under almost all ambient conditionsCapable of explosive decomposition with initiation3 Special HazardsToxic (H401 or H411)
4Can be lethalVapourise at atmospheric pressure & ambient temperatureCapable of explosive decomposition4 Special HazardsVery Toxic (H400 or H410)

Emergency Response cards develop this numerical risk ranking approach and consider the operating conditions (Pressure & Temperature) on the basis that the more extreme the conditions under which the material is handled and/or the more material there is and/or the more exposed or vulnerable the plant is, then the greater the potential for and scale of a loss of containment.

The following overview summarises the concept of a Process Safety Index on which these cards are based:

It must be recognized that innocuous fluids such as water can be hazardous at extreme conditions i.e. high pressure/temperature steam and it may be appropriate to set the minimum Properties value to 1 (rather than 0) for materials that do not generate a conventional score (in NFPA 704 or GHS) to recognise the potential for harm.

The following Process (Condition) parameters are proposed based on design conditions. Remember these are a simple relative tranking in order for initial and subsequent responders to make better informed decisions to deploy limited resources and prioritise activities under often stressful conditions.


The pressure within the asset contributes to both the potential for release (greater stress) and the scale of release (greater distance).

Note that vacuum conditions have a higher score than atmospheric pressure due to the potential for implosion.

0Atmospheric between -2.5 mbar and +7.5 mbar (-1” wg and +3” wg)
1Vacuum below -2.5 mbar (-1” wg)
2Up to 10 barG (150 psig)
3Up to 100 barG (1500 psig)
4Above 100 barG (1500 psig)


Similarly, the temperature of/within the asset contributes to both the potential for release (greater stress) and the scale of release (greater distance).

Note that cryogenic conditions have a higher score than ambient temperature due to the potential for low-temperature failure.

0Ambient between -29 °C and +60 °C (-20 °F and 140 °F)
1Cryogenic below -29 °C (-20 °F) e.g. steel embrittlement
2Up to 100 °C (212 °F) e.g. water boiling point
3Above flashpoint or up to 200 °C (392 °F) e.g. steel deformation
4Above autoignition temperature or above 200 °C (392 °F)


The mass or volume of hazardous material that could potential be released is a key considerationm when judging which assets to protect or isolate in an emergency, therefore a relative ranking scale based on ANSI/API RP 754 (Process Safety Performance Indicators for the Refining and Petrochemical Industries) Tables 1 & 2 (Material Release Threshold Quantities):

Material Hazard Classification1234
Toxic Inhalation Hazard (TIH) Zone A Materials
LC50 less than or equal to 200 ppm
Toxic Inhalation Hazard (TIH) Zone B Materials
LC50 greater than 200 ppm and less than or equal to 1000 ppm
Toxic Inhalation Hazard (TIH) Zone C Materials
LC50 greater than 1000 ppm and less than or equal to 3000 ppmv
Toxic Inhalation Hazard (TIH) Zone D Materials
LC50 greater than 3000 ppm or less than or equal to 5000 ppm
1002001,000 2,000
• Flammable Gases
• Liquids with Initial Boiling Point ≤ 35 °C (95 °F) and Flash Point < 23 °C (73 °F)
• Other Packing Group I Materials excluding strong acids/bases
• Liquids with a Initial Boiling Point > 35 °C (95 °F) and Flash Point < 60 °C (140 °F) • Liquids with Flash Point > 60 °C (140 °F) released at or above Flash Point
• Other Packing Group II and III Materials excluding moderate acids/bases
• Strong acids and bases
• Liquids with Flash Point > 60 °C (140 °F) released at a temperature below Flash Point
• Moderate acids/bases
5,000 10,00010,0020,00
Weights are in kg

This is based on 10 x TQ (Threshold Quantities) in the API 754 tables – other ranking systems can be developed. Basically the greater the mass of hazardous material in the asset/equipment, the higher the Inventory score.

Inhalation Toxicity LC50 is the abbreviation used for the exposure concentration of a toxic substance lethal to half of the test animals – this applies to Toxic Vapours and is derived from Annex B of API 754.

For Toxic Liquids, the following definitions apply:

Packing GroupOral Toxicity
LD50 (mg/kg)
Dermal Toxicity
LD50 (mg/kg)
Inhalation Toxicity
LC50 (mg/L)
I≤ 5≤ 50≤ 0.2
II> 5 and ≤ 50> 50 and ≤ 200> 0.2 and ≤ 2
III> 50 and ≤ 300> 200 and ≤ 1000> 2 and ≤ 4

These are also taken from Annex B of API 754, where LD50 is the abbreviation used for the dose which kills 50% of the test population.


Cards can include images of identified equipment or plant areas. These could be photographs, CAD models, plot plans etc.

We recognise that it’s impractical to develop a set that covers all chemicals, therefore we welcome site, company or industry specific enquiries where we can develop an appropriate deck of relevant materials/equipment.

Pocket (card) size plot or site plans can be included in the box of cards to help orientate/navigate within the facility during the emergency ; particularly useful for offsite responders who are unfamiliar with the layout & equipment.


Preparation for future emergencies should consider related incidents and exploit that experience.

For information on our Incidents Cards, please click on the icon below:

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For more information on Emergency Response cards, options & pricing, please contact us.