diff --git a/definitions/grib2/tables/34/4.2.20.2.table b/definitions/grib2/tables/34/4.2.20.2.table
index d6b9083d1..5600a9959 100644
--- a/definitions/grib2/tables/34/4.2.20.2.table
+++ b/definitions/grib2/tables/34/4.2.20.2.table
@@ -1,5 +1,6 @@
 # Product discipline 20 - Health and socioeconomic impacts, parameter category 2: socioeconomic indicators
 0 0 Population density (Person m-2)
-# 1-191 Reserved
+1 1 Hazard index (Code table 4.254)
+# 2-191 Reserved
 # 192-254 Reserved for local use
 255 255 Missing
diff --git a/definitions/grib2/tables/34/4.253.table b/definitions/grib2/tables/34/4.253.table
new file mode 100644
index 000000000..5893879e2
--- /dev/null
+++ b/definitions/grib2/tables/34/4.253.table
@@ -0,0 +1,91 @@
+# Code table 4.253 - Hazard profiles
+0 0 Reserved
+1 1 Downburst
+2 2 Lightning (Electrical Storm)
+3 3 Thunderstorm
+4 4 Coastal Flood
+5 5 Estuarine (Coastal) Flood
+6 6 Flash Flood
+7 7 Fluvial (Riverine) Flood
+8 8 Groundwater Flood
+9 9 Ice-Jam Flood Including Debris
+10 10 Ponding (Drainage) Flood
+11 11 Snowmelt Flood
+12 12 Surface Water Flooding
+13 13 Glacial Lake Outburst Flood
+14 14 Black Carbon (Brown Clouds)
+15 15 Dust storm or Sandstorm
+16 16 Fog
+17 17 Haze
+18 18 Polluted Air
+19 19 Sand haze
+20 20 Smoke
+21 21 Ocean Acidification
+22 22 Rogue Wave
+23 23 Sea Water Intrusion
+24 24 Sea Ice (Ice Bergs)
+25 25 Ice Flow
+26 26 Seiche
+27 27 Storm Surge
+28 28 Storm Tides
+29 29 Tsunami
+30 30 Depression or Cyclone (Low Pressure Area) (Pressure-Related)
+31 31 Extra-tropical Cyclone (Pressure-Related)
+32 32 Sub-Tropical Cyclone (Pressure-Related)
+33 33 Acid Rain
+34 34 Blizzard
+35 35 Drought
+36 36 Hail
+37 37 Ice Storm
+38 38 Snow
+39 39 Snow Storm
+40 40 Cold Wave
+41 41 Dzud
+42 42 Freeze
+43 43 Frost (Hoar Frost)
+44 44 Freezing Rain (Supercooled Rain)
+45 45 Glaze
+46 46 Ground Frost
+47 47 Heatwave
+48 48 Icing (Including Ice)
+49 49 Thaw
+50 50 Avalanche
+51 51 Mud Flow
+52 52 Rock slide
+53 53 Derecho
+54 54 Gale (Strong Gale)
+55 55 Squall
+56 56 Subtropical Storm
+57 57 Tropical Cyclone (Cyclonic Wind, Rain [Storm] Surge) (Wind-Related)
+58 58 Tropical Storm (Wind-Related)
+59 59 Tornado
+60 60 Wind
+# 61-100 Reserved for meteorological and hydrological hazard indices
+101 101 Household Air Pollution
+102 101 Air Pollution (Point Source)
+103 101 Ambient (Outdoor) Air Pollution
+104 101 Land Degradation
+105 101 Soil Degradation
+106 101 Runoff / Nonpoint Source Pollution 
+107 101 Salinity
+108 101 Biodiversity Loss
+109 101 Deforestation
+110 110 Forest Declines and Diebacks
+111 110 Forest Disturbances
+112 110 Forest Invasive Species
+113 110 Wildfires
+114 110 Desertification
+115 110 Loss of Mangroves
+116 110 Wetland Loss/Degradation
+117 110 Coral Bleaching
+118 110 Compressive Soils
+119 110 Soil Erosion
+120 120 Coastal Erosion and Shoreline Change
+121 120 Permafrost Loss
+122 120 Sand Mining
+123 120 Sea Level Rise
+124 120 Eutrophication
+# 125-200 Reserved for environmental hazard indices
+# 201-32767 Reserved for additional official hazard indices
+# 32768-65534 Reserved for local use
+65535 65535 Missing
diff --git a/definitions/grib2/tables/34/4.254.table b/definitions/grib2/tables/34/4.254.table
new file mode 100644
index 000000000..22523f289
--- /dev/null
+++ b/definitions/grib2/tables/34/4.254.table
@@ -0,0 +1,5 @@
+# Code table 4.254 - Hazard index
+0 0 Undefined
+# 1-191 Reserved - The hazard index can be locally defined by the centre
+# 192-254 Reserved for local use
+255 255 Missing
\ No newline at end of file
diff --git a/definitions/grib2/templates/template.4.148.def b/definitions/grib2/templates/template.4.148.def
new file mode 100644
index 000000000..9451205cd
--- /dev/null
+++ b/definitions/grib2/templates/template.4.148.def
@@ -0,0 +1,10 @@
+# (C) Copyright 2005- ECMWF.
+
+# TEMPLATE 4.148, Analysis or forecast at a horizontal level or in a horizontal layer at a point in time for hazards
+
+include "grib2/templates/template.4.parameter.def"
+include "grib2/templates/template.4.hazards.def"
+include "grib2/templates/template.4.generating_process.def"
+include "grib2/templates/template.4.forecast_time.def"
+include "grib2/templates/template.4.point_in_time.def"
+include "grib2/templates/template.4.horizontal.def"
\ No newline at end of file
diff --git a/definitions/grib2/templates/template.4.149.def b/definitions/grib2/templates/template.4.149.def
new file mode 100644
index 000000000..fd287494b
--- /dev/null
+++ b/definitions/grib2/templates/template.4.149.def
@@ -0,0 +1,11 @@
+# (C) Copyright 2005- ECMWF.
+
+# TEMPLATE 4.149, Individual ensemble forecast, control and perturbed, at a horizontal level or in a horizontal layer at a point in time for hazards
+
+include "grib2/templates/template.4.parameter.def"
+include "grib2/templates/template.4.hazards.def"
+include "grib2/templates/template.4.generating_process.def"
+include "grib2/templates/template.4.forecast_time.def"
+include "grib2/templates/template.4.point_in_time.def"
+include "grib2/templates/template.4.horizontal.def"
+include "grib2/templates/template.4.leps.def"
\ No newline at end of file
diff --git a/definitions/grib2/templates/template.4.150.def b/definitions/grib2/templates/template.4.150.def
new file mode 100644
index 000000000..0cd1745a6
--- /dev/null
+++ b/definitions/grib2/templates/template.4.150.def
@@ -0,0 +1,10 @@
+# (C) Copyright 2005- ECMWF.
+
+# TEMPLATE 4.150, Average, accumulation, extreme values or other statistically processed values, at a horizontal level or in a horizontal layer in a continuous or non-continuous time interval for hazards
+
+include "grib2/templates/template.4.parameter.def"
+include "grib2/templates/template.4.hazards.def"
+include "grib2/templates/template.4.generating_process.def"
+include "grib2/templates/template.4.forecast_time.def"
+include "grib2/templates/template.4.horizontal.def"
+include "grib2/templates/template.4.statistical.def"
\ No newline at end of file
diff --git a/definitions/grib2/templates/template.4.151.def b/definitions/grib2/templates/template.4.151.def
new file mode 100644
index 000000000..24189cfb7
--- /dev/null
+++ b/definitions/grib2/templates/template.4.151.def
@@ -0,0 +1,11 @@
+# (C) Copyright 2005- ECMWF.
+
+# TEMPLATE 4.150, Individual ensemble forecast, control and perturbed, at a horizontal level or in a horizontal layer, in a continuous or non-continuous interval, for hazards
+
+include "grib2/templates/template.4.parameter.def"
+include "grib2/templates/template.4.hazards.def"
+include "grib2/templates/template.4.generating_process.def"
+include "grib2/templates/template.4.forecast_time.def"
+include "grib2/templates/template.4.horizontal.def"
+include "grib2/templates/template.4.leps.def"
+include "grib2/templates/template.4.statistical.def"
\ No newline at end of file
diff --git a/definitions/grib2/templates/template.4.hazards.def b/definitions/grib2/templates/template.4.hazards.def
new file mode 100644
index 000000000..9f99bcac5
--- /dev/null
+++ b/definitions/grib2/templates/template.4.hazards.def
@@ -0,0 +1,12 @@
+# (C) Copyright 2005- ECMWF.
+# Template for hazard profiles
+
+codetable[2] hazardProfile ('4.253.table',masterDir,localDir) : dump;
+
+# The input process identifier shall have the value of the 'analysis or forecast process identifier' of the
+# original GRIB message used as input of the post-processing
+unsigned[2] inputProcessIdentifier : dump,edition_specific;
+
+# The input originating centre shall have the value of the 'originating centre' of the original GRIB message
+# used as input of the post-processing
+codetable[2] inputOriginatingCentre 'common/c-11.table' : dump,edition_specific,string_type;
\ No newline at end of file