diff --git a/operations/helm/tests/metamonitoring-values-generated/mimir-distributed/templates/metamonitoring/mixin-alerts.yaml b/operations/helm/tests/metamonitoring-values-generated/mimir-distributed/templates/metamonitoring/mixin-alerts.yaml
index 99a7f7cf5d8..916c9354eae 100644
--- a/operations/helm/tests/metamonitoring-values-generated/mimir-distributed/templates/metamonitoring/mixin-alerts.yaml
+++ b/operations/helm/tests/metamonitoring-values-generated/mimir-distributed/templates/metamonitoring/mixin-alerts.yaml
@@ -1181,27 +1181,35 @@ spec:
               runbook_url: https://grafana.com/docs/mimir/latest/operators-guide/mimir-runbooks/#mimirblockbuildernocycleprocessing
             expr: |
               max by(cluster, namespace, pod) (histogram_count(increase(cortex_blockbuilder_consume_cycle_duration_seconds[60m]))) == 0
-            for: 5m
+            for: 20m
             labels:
-              severity: warning
+              severity: critical
           - alert: MimirBlockBuilderLagging
             annotations:
-              message: Mimir {{ $labels.pod }} in {{ $labels.cluster }}/{{ $labels.namespace }} reports partition lag of {{ printf "%.2f" $value }}%.
+              message: Mimir {{ $labels.pod }} in {{ $labels.cluster }}/{{ $labels.namespace }} reports partition lag of {{ printf "%.2f" $value }}.
               runbook_url: https://grafana.com/docs/mimir/latest/operators-guide/mimir-runbooks/#mimirblockbuilderlagging
             expr: |
               max by(cluster, namespace, pod) (max_over_time(cortex_blockbuilder_consumer_lag_records[10m])) > 4e6
             for: 75m
             labels:
               severity: warning
+          - alert: MimirBlockBuilderLagging
+            annotations:
+              message: Mimir {{ $labels.pod }} in {{ $labels.cluster }}/{{ $labels.namespace }} reports partition lag of {{ printf "%.2f" $value }}.
+              runbook_url: https://grafana.com/docs/mimir/latest/operators-guide/mimir-runbooks/#mimirblockbuilderlagging
+            expr: |
+              max by(cluster, namespace, pod) (max_over_time(cortex_blockbuilder_consumer_lag_records[10m])) > 4e6
+            for: 140m
+            labels:
+              severity: critical
           - alert: MimirBlockBuilderCompactAndUploadFailed
             annotations:
               message: Mimir {{ $labels.pod }} in {{ $labels.cluster }}/{{ $labels.namespace }} fails to compact and upload blocks.
               runbook_url: https://grafana.com/docs/mimir/latest/operators-guide/mimir-runbooks/#mimirblockbuildercompactanduploadfailed
             expr: |
               sum by (cluster, namespace, pod) (rate(cortex_blockbuilder_tsdb_compact_and_upload_failed_total[1m])) > 0
-            for: 5m
             labels:
-              severity: warning
+              severity: critical
       - name: mimir_continuous_test
         rules:
           - alert: MimirContinuousTestNotRunningOnWrites
diff --git a/operations/mimir-mixin-compiled-baremetal/alerts.yaml b/operations/mimir-mixin-compiled-baremetal/alerts.yaml
index ae02e2a1e65..85570d950c4 100644
--- a/operations/mimir-mixin-compiled-baremetal/alerts.yaml
+++ b/operations/mimir-mixin-compiled-baremetal/alerts.yaml
@@ -1155,27 +1155,35 @@ groups:
             runbook_url: https://grafana.com/docs/mimir/latest/operators-guide/mimir-runbooks/#mimirblockbuildernocycleprocessing
           expr: |
             max by(cluster, namespace, instance) (histogram_count(increase(cortex_blockbuilder_consume_cycle_duration_seconds[60m]))) == 0
-          for: 5m
+          for: 20m
           labels:
-            severity: warning
+            severity: critical
         - alert: MimirBlockBuilderLagging
           annotations:
-            message: Mimir {{ $labels.instance }} in {{ $labels.cluster }}/{{ $labels.namespace }} reports partition lag of {{ printf "%.2f" $value }}%.
+            message: Mimir {{ $labels.instance }} in {{ $labels.cluster }}/{{ $labels.namespace }} reports partition lag of {{ printf "%.2f" $value }}.
             runbook_url: https://grafana.com/docs/mimir/latest/operators-guide/mimir-runbooks/#mimirblockbuilderlagging
           expr: |
             max by(cluster, namespace, instance) (max_over_time(cortex_blockbuilder_consumer_lag_records[10m])) > 4e6
           for: 75m
           labels:
             severity: warning
+        - alert: MimirBlockBuilderLagging
+          annotations:
+            message: Mimir {{ $labels.instance }} in {{ $labels.cluster }}/{{ $labels.namespace }} reports partition lag of {{ printf "%.2f" $value }}.
+            runbook_url: https://grafana.com/docs/mimir/latest/operators-guide/mimir-runbooks/#mimirblockbuilderlagging
+          expr: |
+            max by(cluster, namespace, instance) (max_over_time(cortex_blockbuilder_consumer_lag_records[10m])) > 4e6
+          for: 140m
+          labels:
+            severity: critical
         - alert: MimirBlockBuilderCompactAndUploadFailed
           annotations:
             message: Mimir {{ $labels.instance }} in {{ $labels.cluster }}/{{ $labels.namespace }} fails to compact and upload blocks.
             runbook_url: https://grafana.com/docs/mimir/latest/operators-guide/mimir-runbooks/#mimirblockbuildercompactanduploadfailed
           expr: |
             sum by (cluster, namespace, instance) (rate(cortex_blockbuilder_tsdb_compact_and_upload_failed_total[1m])) > 0
-          for: 5m
           labels:
-            severity: warning
+            severity: critical
     - name: mimir_continuous_test
       rules:
         - alert: MimirContinuousTestNotRunningOnWrites
diff --git a/operations/mimir-mixin-compiled/alerts.yaml b/operations/mimir-mixin-compiled/alerts.yaml
index be4057ddb7a..63e205a4293 100644
--- a/operations/mimir-mixin-compiled/alerts.yaml
+++ b/operations/mimir-mixin-compiled/alerts.yaml
@@ -1169,27 +1169,35 @@ groups:
             runbook_url: https://grafana.com/docs/mimir/latest/operators-guide/mimir-runbooks/#mimirblockbuildernocycleprocessing
           expr: |
             max by(cluster, namespace, pod) (histogram_count(increase(cortex_blockbuilder_consume_cycle_duration_seconds[60m]))) == 0
-          for: 5m
+          for: 20m
           labels:
-            severity: warning
+            severity: critical
         - alert: MimirBlockBuilderLagging
           annotations:
-            message: Mimir {{ $labels.pod }} in {{ $labels.cluster }}/{{ $labels.namespace }} reports partition lag of {{ printf "%.2f" $value }}%.
+            message: Mimir {{ $labels.pod }} in {{ $labels.cluster }}/{{ $labels.namespace }} reports partition lag of {{ printf "%.2f" $value }}.
             runbook_url: https://grafana.com/docs/mimir/latest/operators-guide/mimir-runbooks/#mimirblockbuilderlagging
           expr: |
             max by(cluster, namespace, pod) (max_over_time(cortex_blockbuilder_consumer_lag_records[10m])) > 4e6
           for: 75m
           labels:
             severity: warning
+        - alert: MimirBlockBuilderLagging
+          annotations:
+            message: Mimir {{ $labels.pod }} in {{ $labels.cluster }}/{{ $labels.namespace }} reports partition lag of {{ printf "%.2f" $value }}.
+            runbook_url: https://grafana.com/docs/mimir/latest/operators-guide/mimir-runbooks/#mimirblockbuilderlagging
+          expr: |
+            max by(cluster, namespace, pod) (max_over_time(cortex_blockbuilder_consumer_lag_records[10m])) > 4e6
+          for: 140m
+          labels:
+            severity: critical
         - alert: MimirBlockBuilderCompactAndUploadFailed
           annotations:
             message: Mimir {{ $labels.pod }} in {{ $labels.cluster }}/{{ $labels.namespace }} fails to compact and upload blocks.
             runbook_url: https://grafana.com/docs/mimir/latest/operators-guide/mimir-runbooks/#mimirblockbuildercompactanduploadfailed
           expr: |
             sum by (cluster, namespace, pod) (rate(cortex_blockbuilder_tsdb_compact_and_upload_failed_total[1m])) > 0
-          for: 5m
           labels:
-            severity: warning
+            severity: critical
     - name: mimir_continuous_test
       rules:
         - alert: MimirContinuousTestNotRunningOnWrites
diff --git a/operations/mimir-mixin/alerts/ingest-storage.libsonnet b/operations/mimir-mixin/alerts/ingest-storage.libsonnet
index b223a0514b7..d92d9279e67 100644
--- a/operations/mimir-mixin/alerts/ingest-storage.libsonnet
+++ b/operations/mimir-mixin/alerts/ingest-storage.libsonnet
@@ -230,12 +230,12 @@
         // Alert if block-builder didn't process cycles in the past hour.
         {
           alert: $.alertName('BlockBuilderNoCycleProcessing'),
-          'for': '5m',
+          'for': '20m',
           expr: |||
             max by(%(alert_aggregation_labels)s, %(per_instance_label)s) (histogram_count(increase(cortex_blockbuilder_consume_cycle_duration_seconds[60m]))) == 0
           ||| % $._config,
           labels: {
-            severity: 'warning',
+            severity: 'critical',
           },
           annotations: {
             message: '%(product)s {{ $labels.%(per_instance_label)s }} in %(alert_aggregation_variables)s has not processed cycles in the past hour.' % $._config,
@@ -255,19 +255,31 @@
             severity: 'warning',
           },
           annotations: {
-            message: '%(product)s {{ $labels.%(per_instance_label)s }} in %(alert_aggregation_variables)s reports partition lag of {{ printf "%%.2f" $value }}%%.' % $._config,
+            message: '%(product)s {{ $labels.%(per_instance_label)s }} in %(alert_aggregation_variables)s reports partition lag of {{ printf "%%.2f" $value }}.' % $._config,
+          },
+        },
+        {
+          alert: $.alertName('BlockBuilderLagging'),
+          'for': '140m',  // 2h20m. Indicating the lag did not come down for ~2 consumption cycles.
+          expr: |||
+            max by(%(alert_aggregation_labels)s, %(per_instance_label)s) (max_over_time(cortex_blockbuilder_consumer_lag_records[10m])) > 4e6
+          ||| % $._config,
+          labels: {
+            severity: 'critical',
+          },
+          annotations: {
+            message: '%(product)s {{ $labels.%(per_instance_label)s }} in %(alert_aggregation_variables)s reports partition lag of {{ printf "%%.2f" $value }}.' % $._config,
           },
         },
 
-        // Alert if block-builder is failing to compact and upload any blocks.
+        // Alert immediately if block-builder is failing to compact and upload any blocks.
         {
           alert: $.alertName('BlockBuilderCompactAndUploadFailed'),
-          'for': '5m',
           expr: |||
             sum by (%(alert_aggregation_labels)s, %(per_instance_label)s) (rate(cortex_blockbuilder_tsdb_compact_and_upload_failed_total[1m])) > 0
           ||| % $._config,
           labels: {
-            severity: 'warning',
+            severity: 'critical',
           },
           annotations: {
             message: '%(product)s {{ $labels.%(per_instance_label)s }} in %(alert_aggregation_variables)s fails to compact and upload blocks.' % $._config,