diff --git a/src/OpenTelemetry.Api/Baggage.cs b/src/OpenTelemetry.Api/Baggage.cs
index 087dead3342..3dddf60ef89 100644
--- a/src/OpenTelemetry.Api/Baggage.cs
+++ b/src/OpenTelemetry.Api/Baggage.cs
@@ -377,7 +377,7 @@ private static BaggageHolder EnsureBaggageHolder()
             return baggageHolder;
         }
 
-        private class BaggageHolder
+        private sealed class BaggageHolder
         {
             public Baggage Baggage;
         }
diff --git a/src/OpenTelemetry.Api/Internal/OpenTelemetryApiEventSource.cs b/src/OpenTelemetry.Api/Internal/OpenTelemetryApiEventSource.cs
index 0c802e3c2c0..55f1bd54c09 100644
--- a/src/OpenTelemetry.Api/Internal/OpenTelemetryApiEventSource.cs
+++ b/src/OpenTelemetry.Api/Internal/OpenTelemetryApiEventSource.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Internal
     /// This is used for internal logging of this library.
     /// </summary>
     [EventSource(Name = "OpenTelemetry-Api")]
-    internal class OpenTelemetryApiEventSource : EventSource
+    internal sealed class OpenTelemetryApiEventSource : EventSource
     {
         public static OpenTelemetryApiEventSource Log = new();
 
diff --git a/src/OpenTelemetry.Exporter.Jaeger/ApacheThrift/Protocol/TProtocolException.cs b/src/OpenTelemetry.Exporter.Jaeger/ApacheThrift/Protocol/TProtocolException.cs
index f2f47895190..8e6d3a8121f 100644
--- a/src/OpenTelemetry.Exporter.Jaeger/ApacheThrift/Protocol/TProtocolException.cs
+++ b/src/OpenTelemetry.Exporter.Jaeger/ApacheThrift/Protocol/TProtocolException.cs
@@ -1,4 +1,4 @@
-// <auto-generated/> (Turns off StyleCop analysis in this file.)
+// <auto-generated/> (Turns off StyleCop analysis in this file.)
 
 // Licensed to the Apache Software Foundation(ASF) under one
 // or more contributor license agreements.See the NOTICE file
diff --git a/src/OpenTelemetry.Exporter.Jaeger/ApacheThrift/TException.cs b/src/OpenTelemetry.Exporter.Jaeger/ApacheThrift/TException.cs
index a7040f0153e..14d46fe6ad4 100644
--- a/src/OpenTelemetry.Exporter.Jaeger/ApacheThrift/TException.cs
+++ b/src/OpenTelemetry.Exporter.Jaeger/ApacheThrift/TException.cs
@@ -1,4 +1,4 @@
-// <auto-generated/> (Turns off StyleCop analysis in this file.)
+// <auto-generated/> (Turns off StyleCop analysis in this file.)
 
 // Licensed to the Apache Software Foundation(ASF) under one
 // or more contributor license agreements.See the NOTICE file
diff --git a/src/OpenTelemetry.Exporter.Jaeger/Implementation/JaegerExporterEventSource.cs b/src/OpenTelemetry.Exporter.Jaeger/Implementation/JaegerExporterEventSource.cs
index c22dd408b65..f3fee3b9da3 100644
--- a/src/OpenTelemetry.Exporter.Jaeger/Implementation/JaegerExporterEventSource.cs
+++ b/src/OpenTelemetry.Exporter.Jaeger/Implementation/JaegerExporterEventSource.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Exporter.Jaeger.Implementation
     /// EventSource events emitted from the project.
     /// </summary>
     [EventSource(Name = "OpenTelemetry-Exporter-Jaeger")]
-    internal class JaegerExporterEventSource : EventSource
+    internal sealed class JaegerExporterEventSource : EventSource
     {
         public static JaegerExporterEventSource Log = new();
 
diff --git a/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/Implementation/OpenTelemetryProtocolExporterEventSource.cs b/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/Implementation/OpenTelemetryProtocolExporterEventSource.cs
index 17db6324a1b..80351d19f28 100644
--- a/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/Implementation/OpenTelemetryProtocolExporterEventSource.cs
+++ b/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/Implementation/OpenTelemetryProtocolExporterEventSource.cs
@@ -21,7 +21,7 @@
 namespace OpenTelemetry.Exporter.OpenTelemetryProtocol.Implementation
 {
     [EventSource(Name = "OpenTelemetry-Exporter-OpenTelemetryProtocol")]
-    internal class OpenTelemetryProtocolExporterEventSource : EventSource
+    internal sealed class OpenTelemetryProtocolExporterEventSource : EventSource
     {
         public static readonly OpenTelemetryProtocolExporterEventSource Log = new();
 
diff --git a/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OtlpLogExporter.cs b/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OtlpLogExporter.cs
index 8bcde202e7f..9ca0e4570f0 100644
--- a/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OtlpLogExporter.cs
+++ b/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OtlpLogExporter.cs
@@ -28,7 +28,7 @@ namespace OpenTelemetry.Exporter
     /// Exporter consuming <see cref="LogRecord"/> and exporting the data using
     /// the OpenTelemetry protocol (OTLP).
     /// </summary>
-    internal class OtlpLogExporter : BaseExporter<LogRecord>
+    internal sealed class OtlpLogExporter : BaseExporter<LogRecord>
     {
         private readonly SdkLimitOptions sdkLimitOptions;
         private readonly IExportClient<OtlpCollector.ExportLogsServiceRequest> exportClient;
diff --git a/src/OpenTelemetry.Exporter.ZPages/Implementation/ZPagesActivityAggregate.cs b/src/OpenTelemetry.Exporter.ZPages/Implementation/ZPagesActivityAggregate.cs
index 842210b2473..2887989bbc0 100644
--- a/src/OpenTelemetry.Exporter.ZPages/Implementation/ZPagesActivityAggregate.cs
+++ b/src/OpenTelemetry.Exporter.ZPages/Implementation/ZPagesActivityAggregate.cs
@@ -22,7 +22,7 @@ namespace OpenTelemetry.Exporter.ZPages.Implementation
     /// <summary>
     /// Stores the activity information aggregated according to activity name.
     /// </summary>
-    internal class ZPagesActivityAggregate
+    internal sealed class ZPagesActivityAggregate
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="ZPagesActivityAggregate"/> class.
diff --git a/src/OpenTelemetry.Exporter.ZPages/Implementation/ZPagesExporterEventSource.cs b/src/OpenTelemetry.Exporter.ZPages/Implementation/ZPagesExporterEventSource.cs
index f0b8dec0b5b..cba2dbffa2d 100644
--- a/src/OpenTelemetry.Exporter.ZPages/Implementation/ZPagesExporterEventSource.cs
+++ b/src/OpenTelemetry.Exporter.ZPages/Implementation/ZPagesExporterEventSource.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Exporter.ZPages.Implementation
     /// EventSource events emitted from the project.
     /// </summary>
     [EventSource(Name = "OpenTelemetry-Exporter-ZPages")]
-    internal class ZPagesExporterEventSource : EventSource
+    internal sealed class ZPagesExporterEventSource : EventSource
     {
         public static ZPagesExporterEventSource Log = new();
 
diff --git a/src/OpenTelemetry.Exporter.ZPages/Implementation/ZPagesStatsBuilder.cs b/src/OpenTelemetry.Exporter.ZPages/Implementation/ZPagesStatsBuilder.cs
index 03648422ef3..2409d02ef86 100644
--- a/src/OpenTelemetry.Exporter.ZPages/Implementation/ZPagesStatsBuilder.cs
+++ b/src/OpenTelemetry.Exporter.ZPages/Implementation/ZPagesStatsBuilder.cs
@@ -16,7 +16,7 @@
 
 namespace OpenTelemetry.Exporter.ZPages.Implementation
 {
-    internal class ZPagesStatsBuilder
+    internal sealed class ZPagesStatsBuilder
     {
         public const string ContentType = "text/html";
     }
diff --git a/src/OpenTelemetry.Exporter.Zipkin/Implementation/ZipkinEndpoint.cs b/src/OpenTelemetry.Exporter.Zipkin/Implementation/ZipkinEndpoint.cs
index db850fc3f5c..0d4fc8705d3 100644
--- a/src/OpenTelemetry.Exporter.Zipkin/Implementation/ZipkinEndpoint.cs
+++ b/src/OpenTelemetry.Exporter.Zipkin/Implementation/ZipkinEndpoint.cs
@@ -19,7 +19,7 @@
 
 namespace OpenTelemetry.Exporter.Zipkin.Implementation
 {
-    internal class ZipkinEndpoint
+    internal sealed class ZipkinEndpoint
     {
         public ZipkinEndpoint(string serviceName)
             : this(serviceName, null, null, null, null)
diff --git a/src/OpenTelemetry.Exporter.Zipkin/Implementation/ZipkinExporterEventSource.cs b/src/OpenTelemetry.Exporter.Zipkin/Implementation/ZipkinExporterEventSource.cs
index a7c4d317b3e..c60bc053a01 100644
--- a/src/OpenTelemetry.Exporter.Zipkin/Implementation/ZipkinExporterEventSource.cs
+++ b/src/OpenTelemetry.Exporter.Zipkin/Implementation/ZipkinExporterEventSource.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Exporter.Zipkin.Implementation
     /// EventSource events emitted from the project.
     /// </summary>
     [EventSource(Name = "OpenTelemetry-Exporter-Zipkin")]
-    internal class ZipkinExporterEventSource : EventSource
+    internal sealed class ZipkinExporterEventSource : EventSource
     {
         public static ZipkinExporterEventSource Log = new();
 
diff --git a/src/OpenTelemetry.Extensions.Hosting/Implementation/HostingExtensionsEventSource.cs b/src/OpenTelemetry.Extensions.Hosting/Implementation/HostingExtensionsEventSource.cs
index fc20083a801..164695c6144 100644
--- a/src/OpenTelemetry.Extensions.Hosting/Implementation/HostingExtensionsEventSource.cs
+++ b/src/OpenTelemetry.Extensions.Hosting/Implementation/HostingExtensionsEventSource.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Extensions.Hosting.Implementation
     /// EventSource events emitted from the project.
     /// </summary>
     [EventSource(Name = "OpenTelemetry-Extensions-Hosting")]
-    internal class HostingExtensionsEventSource : EventSource
+    internal sealed class HostingExtensionsEventSource : EventSource
     {
         public static HostingExtensionsEventSource Log = new();
 
diff --git a/src/OpenTelemetry.Extensions.Propagators/OpenTelemetryPropagatorsEventSource.cs b/src/OpenTelemetry.Extensions.Propagators/OpenTelemetryPropagatorsEventSource.cs
index fc22c92e87f..1e3163a0b12 100644
--- a/src/OpenTelemetry.Extensions.Propagators/OpenTelemetryPropagatorsEventSource.cs
+++ b/src/OpenTelemetry.Extensions.Propagators/OpenTelemetryPropagatorsEventSource.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Internal
     /// This is used for internal logging of this library.
     /// </summary>
     [EventSource(Name = "OpenTelemetry.Extensions.Propagators")]
-    internal class OpenTelemetryPropagatorsEventSource : EventSource
+    internal sealed class OpenTelemetryPropagatorsEventSource : EventSource
     {
         public static OpenTelemetryPropagatorsEventSource Log = new();
 
diff --git a/src/OpenTelemetry.Instrumentation.AspNetCore/AspNetCoreInstrumentation.cs b/src/OpenTelemetry.Instrumentation.AspNetCore/AspNetCoreInstrumentation.cs
index 0503813e69c..190a305aedf 100644
--- a/src/OpenTelemetry.Instrumentation.AspNetCore/AspNetCoreInstrumentation.cs
+++ b/src/OpenTelemetry.Instrumentation.AspNetCore/AspNetCoreInstrumentation.cs
@@ -22,7 +22,7 @@ namespace OpenTelemetry.Instrumentation.AspNetCore
     /// <summary>
     /// Asp.Net Core Requests instrumentation.
     /// </summary>
-    internal class AspNetCoreInstrumentation : IDisposable
+    internal sealed class AspNetCoreInstrumentation : IDisposable
     {
         private static readonly HashSet<string> DiagnosticSourceEvents = new()
         {
diff --git a/src/OpenTelemetry.Instrumentation.AspNetCore/AspNetCoreMetrics.cs b/src/OpenTelemetry.Instrumentation.AspNetCore/AspNetCoreMetrics.cs
index 7f4c2292091..c14b6628eca 100644
--- a/src/OpenTelemetry.Instrumentation.AspNetCore/AspNetCoreMetrics.cs
+++ b/src/OpenTelemetry.Instrumentation.AspNetCore/AspNetCoreMetrics.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Instrumentation.AspNetCore
     /// <summary>
     /// Asp.Net Core Requests instrumentation.
     /// </summary>
-    internal class AspNetCoreMetrics : IDisposable
+    internal sealed class AspNetCoreMetrics : IDisposable
     {
         internal static readonly AssemblyName AssemblyName = typeof(HttpInListener).Assembly.GetName();
         internal static readonly string InstrumentationName = AssemblyName.Name;
diff --git a/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/AspNetCoreInstrumentationEventSource.cs b/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/AspNetCoreInstrumentationEventSource.cs
index c3929f6845b..b78ab6953d0 100644
--- a/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/AspNetCoreInstrumentationEventSource.cs
+++ b/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/AspNetCoreInstrumentationEventSource.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Instrumentation.AspNetCore.Implementation
     /// EventSource events emitted from the project.
     /// </summary>
     [EventSource(Name = "OpenTelemetry-Instrumentation-AspNetCore")]
-    internal class AspNetCoreInstrumentationEventSource : EventSource
+    internal sealed class AspNetCoreInstrumentationEventSource : EventSource
     {
         public static AspNetCoreInstrumentationEventSource Log = new();
 
diff --git a/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInMetricsListener.cs b/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInMetricsListener.cs
index 030c5648623..802feedec04 100644
--- a/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInMetricsListener.cs
+++ b/src/OpenTelemetry.Instrumentation.AspNetCore/Implementation/HttpInMetricsListener.cs
@@ -24,7 +24,7 @@
 
 namespace OpenTelemetry.Instrumentation.AspNetCore.Implementation
 {
-    internal class HttpInMetricsListener : ListenerHandler
+    internal sealed class HttpInMetricsListener : ListenerHandler
     {
         private const string OnStopEvent = "Microsoft.AspNetCore.Hosting.HttpRequestIn.Stop";
 
diff --git a/src/OpenTelemetry.Instrumentation.GrpcNetClient/GrpcClientInstrumentation.cs b/src/OpenTelemetry.Instrumentation.GrpcNetClient/GrpcClientInstrumentation.cs
index 75242e5a876..df827346111 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcNetClient/GrpcClientInstrumentation.cs
+++ b/src/OpenTelemetry.Instrumentation.GrpcNetClient/GrpcClientInstrumentation.cs
@@ -21,7 +21,7 @@ namespace OpenTelemetry.Instrumentation.GrpcNetClient
     /// <summary>
     /// GrpcClient instrumentation.
     /// </summary>
-    internal class GrpcClientInstrumentation : IDisposable
+    internal sealed class GrpcClientInstrumentation : IDisposable
     {
         private readonly DiagnosticSourceSubscriber diagnosticSourceSubscriber;
 
diff --git a/src/OpenTelemetry.Instrumentation.GrpcNetClient/Implementation/GrpcInstrumentationEventSource.cs b/src/OpenTelemetry.Instrumentation.GrpcNetClient/Implementation/GrpcInstrumentationEventSource.cs
index 340ddb73603..c171c21c59b 100644
--- a/src/OpenTelemetry.Instrumentation.GrpcNetClient/Implementation/GrpcInstrumentationEventSource.cs
+++ b/src/OpenTelemetry.Instrumentation.GrpcNetClient/Implementation/GrpcInstrumentationEventSource.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Instrumentation.GrpcNetClient.Implementation
     /// EventSource events emitted from the project.
     /// </summary>
     [EventSource(Name = "OpenTelemetry-Instrumentation-Grpc")]
-    internal class GrpcInstrumentationEventSource : EventSource
+    internal sealed class GrpcInstrumentationEventSource : EventSource
     {
         public static GrpcInstrumentationEventSource Log = new();
 
diff --git a/src/OpenTelemetry.Instrumentation.Http/HttpClientInstrumentation.cs b/src/OpenTelemetry.Instrumentation.Http/HttpClientInstrumentation.cs
index 09fc1f3c0ae..4c7a42a0cb4 100644
--- a/src/OpenTelemetry.Instrumentation.Http/HttpClientInstrumentation.cs
+++ b/src/OpenTelemetry.Instrumentation.Http/HttpClientInstrumentation.cs
@@ -21,7 +21,7 @@ namespace OpenTelemetry.Instrumentation.Http
     /// <summary>
     /// HttpClient instrumentation.
     /// </summary>
-    internal class HttpClientInstrumentation : IDisposable
+    internal sealed class HttpClientInstrumentation : IDisposable
     {
         private readonly DiagnosticSourceSubscriber diagnosticSourceSubscriber;
 
diff --git a/src/OpenTelemetry.Instrumentation.Http/HttpClientMetrics.cs b/src/OpenTelemetry.Instrumentation.Http/HttpClientMetrics.cs
index c0502219e3b..27b39f5da17 100644
--- a/src/OpenTelemetry.Instrumentation.Http/HttpClientMetrics.cs
+++ b/src/OpenTelemetry.Instrumentation.Http/HttpClientMetrics.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Instrumentation.Http
     /// <summary>
     /// HttpClient instrumentation.
     /// </summary>
-    internal class HttpClientMetrics : IDisposable
+    internal sealed class HttpClientMetrics : IDisposable
     {
         internal static readonly AssemblyName AssemblyName = typeof(HttpClientMetrics).Assembly.GetName();
         internal static readonly string InstrumentationName = AssemblyName.Name;
diff --git a/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerMetricsDiagnosticListener.cs b/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerMetricsDiagnosticListener.cs
index 2e8234f00db..8b2ebf0a678 100644
--- a/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerMetricsDiagnosticListener.cs
+++ b/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpHandlerMetricsDiagnosticListener.cs
@@ -22,7 +22,7 @@
 
 namespace OpenTelemetry.Instrumentation.Http.Implementation
 {
-    internal class HttpHandlerMetricsDiagnosticListener : ListenerHandler
+    internal sealed class HttpHandlerMetricsDiagnosticListener : ListenerHandler
     {
         internal const string OnStopEvent = "System.Net.Http.HttpRequestOut.Stop";
 
diff --git a/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpInstrumentationEventSource.cs b/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpInstrumentationEventSource.cs
index 746d4d873a0..a0a5e6fa967 100644
--- a/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpInstrumentationEventSource.cs
+++ b/src/OpenTelemetry.Instrumentation.Http/Implementation/HttpInstrumentationEventSource.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Instrumentation.Http.Implementation
     /// EventSource events emitted from the project.
     /// </summary>
     [EventSource(Name = "OpenTelemetry-Instrumentation-Http")]
-    internal class HttpInstrumentationEventSource : EventSource
+    internal sealed class HttpInstrumentationEventSource : EventSource
     {
         public static HttpInstrumentationEventSource Log = new();
 
diff --git a/src/OpenTelemetry.Instrumentation.SqlClient/Implementation/SqlActivitySourceHelper.cs b/src/OpenTelemetry.Instrumentation.SqlClient/Implementation/SqlActivitySourceHelper.cs
index 95c68fda943..fbf4fb7d83a 100644
--- a/src/OpenTelemetry.Instrumentation.SqlClient/Implementation/SqlActivitySourceHelper.cs
+++ b/src/OpenTelemetry.Instrumentation.SqlClient/Implementation/SqlActivitySourceHelper.cs
@@ -25,7 +25,7 @@ namespace OpenTelemetry.Instrumentation.SqlClient.Implementation
     /// Helper class to hold common properties used by both SqlClientDiagnosticListener on .NET Core
     /// and SqlEventSourceListener on .NET Framework.
     /// </summary>
-    internal class SqlActivitySourceHelper
+    internal sealed class SqlActivitySourceHelper
     {
         public const string MicrosoftSqlServerDatabaseSystemName = "mssql";
 
diff --git a/src/OpenTelemetry.Instrumentation.SqlClient/Implementation/SqlClientInstrumentationEventSource.cs b/src/OpenTelemetry.Instrumentation.SqlClient/Implementation/SqlClientInstrumentationEventSource.cs
index 2011b4b74bf..31a7a9737bf 100644
--- a/src/OpenTelemetry.Instrumentation.SqlClient/Implementation/SqlClientInstrumentationEventSource.cs
+++ b/src/OpenTelemetry.Instrumentation.SqlClient/Implementation/SqlClientInstrumentationEventSource.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Instrumentation.SqlClient.Implementation
     /// EventSource events emitted from the project.
     /// </summary>
     [EventSource(Name = "OpenTelemetry-Instrumentation-SqlClient")]
-    internal class SqlClientInstrumentationEventSource : EventSource
+    internal sealed class SqlClientInstrumentationEventSource : EventSource
     {
         public static SqlClientInstrumentationEventSource Log = new();
 
diff --git a/src/OpenTelemetry.Instrumentation.SqlClient/SqlClientInstrumentation.cs b/src/OpenTelemetry.Instrumentation.SqlClient/SqlClientInstrumentation.cs
index 5b293bf76d0..0b4469aefe3 100644
--- a/src/OpenTelemetry.Instrumentation.SqlClient/SqlClientInstrumentation.cs
+++ b/src/OpenTelemetry.Instrumentation.SqlClient/SqlClientInstrumentation.cs
@@ -21,7 +21,7 @@ namespace OpenTelemetry.Instrumentation.SqlClient
     /// <summary>
     /// SqlClient instrumentation.
     /// </summary>
-    internal class SqlClientInstrumentation : IDisposable
+    internal sealed class SqlClientInstrumentation : IDisposable
     {
         internal const string SqlClientDiagnosticListenerName = "SqlClientDiagnosticListener";
 
diff --git a/src/OpenTelemetry.Instrumentation.SqlClient/SqlClientInstrumentationOptions.cs b/src/OpenTelemetry.Instrumentation.SqlClient/SqlClientInstrumentationOptions.cs
index 3074bf2b372..b413952e6cf 100644
--- a/src/OpenTelemetry.Instrumentation.SqlClient/SqlClientInstrumentationOptions.cs
+++ b/src/OpenTelemetry.Instrumentation.SqlClient/SqlClientInstrumentationOptions.cs
@@ -270,7 +270,7 @@ internal void AddConnectionLevelDetailsToActivity(string dataSource, Activity sq
             }
         }
 
-        internal class SqlConnectionDetails
+        internal sealed class SqlConnectionDetails
         {
             public string ServerHostName { get; set; }
 
diff --git a/src/OpenTelemetry.Shims.OpenTracing/ScopeManagerShim.cs b/src/OpenTelemetry.Shims.OpenTracing/ScopeManagerShim.cs
index a4039d88a41..0617a16cbe7 100644
--- a/src/OpenTelemetry.Shims.OpenTracing/ScopeManagerShim.cs
+++ b/src/OpenTelemetry.Shims.OpenTracing/ScopeManagerShim.cs
@@ -95,7 +95,7 @@ public IScope Activate(ISpan span, bool finishSpanOnDispose)
             return instrumentation;
         }
 
-        private class ScopeInstrumentation : IScope
+        private sealed class ScopeInstrumentation : IScope
         {
             private readonly Action disposeAction;
 
diff --git a/src/OpenTelemetry/DiagnosticSourceInstrumentation/DiagnosticSourceListener.cs b/src/OpenTelemetry/DiagnosticSourceInstrumentation/DiagnosticSourceListener.cs
index 43a78008272..9e8f68c2498 100644
--- a/src/OpenTelemetry/DiagnosticSourceInstrumentation/DiagnosticSourceListener.cs
+++ b/src/OpenTelemetry/DiagnosticSourceInstrumentation/DiagnosticSourceListener.cs
@@ -21,7 +21,7 @@
 
 namespace OpenTelemetry.Instrumentation
 {
-    internal class DiagnosticSourceListener : IObserver<KeyValuePair<string, object>>
+    internal sealed class DiagnosticSourceListener : IObserver<KeyValuePair<string, object>>
     {
         private readonly ListenerHandler handler;
 
diff --git a/src/OpenTelemetry/DiagnosticSourceInstrumentation/InstrumentationEventSource.cs b/src/OpenTelemetry/DiagnosticSourceInstrumentation/InstrumentationEventSource.cs
index 0590edb5111..6e1760bfccd 100644
--- a/src/OpenTelemetry/DiagnosticSourceInstrumentation/InstrumentationEventSource.cs
+++ b/src/OpenTelemetry/DiagnosticSourceInstrumentation/InstrumentationEventSource.cs
@@ -24,7 +24,7 @@ namespace OpenTelemetry.Instrumentation
     /// EventSource events emitted from the project.
     /// </summary>
     [EventSource(Name = "OpenTelemetry-Instrumentation")]
-    internal class InstrumentationEventSource : EventSource
+    internal sealed class InstrumentationEventSource : EventSource
     {
         public static InstrumentationEventSource Log = new();
 
diff --git a/src/OpenTelemetry/DiagnosticSourceInstrumentation/PropertyFetcher.cs b/src/OpenTelemetry/DiagnosticSourceInstrumentation/PropertyFetcher.cs
index d2ec900b051..6c1657fe657 100644
--- a/src/OpenTelemetry/DiagnosticSourceInstrumentation/PropertyFetcher.cs
+++ b/src/OpenTelemetry/DiagnosticSourceInstrumentation/PropertyFetcher.cs
@@ -25,7 +25,7 @@ namespace OpenTelemetry.Instrumentation
     /// PropertyFetcher fetches a property from an object.
     /// </summary>
     /// <typeparam name="T">The type of the property being fetched.</typeparam>
-    internal class PropertyFetcher<T>
+    internal sealed class PropertyFetcher<T>
     {
         private readonly string propertyName;
         private PropertyFetch innerFetcher;
diff --git a/src/OpenTelemetry/Internal/OpenTelemetrySdkEventSource.cs b/src/OpenTelemetry/Internal/OpenTelemetrySdkEventSource.cs
index 5aa859b5715..063e2fcbe2a 100644
--- a/src/OpenTelemetry/Internal/OpenTelemetrySdkEventSource.cs
+++ b/src/OpenTelemetry/Internal/OpenTelemetrySdkEventSource.cs
@@ -29,7 +29,7 @@ namespace OpenTelemetry.Internal
     /// EventSource implementation for OpenTelemetry SDK implementation.
     /// </summary>
     [EventSource(Name = "OpenTelemetry-Sdk")]
-    internal class OpenTelemetrySdkEventSource : EventSource
+    internal sealed class OpenTelemetrySdkEventSource : EventSource
     {
         public static OpenTelemetrySdkEventSource Log = new();
 #if DEBUG
diff --git a/src/OpenTelemetry/Internal/SelfDiagnosticsConfigParser.cs b/src/OpenTelemetry/Internal/SelfDiagnosticsConfigParser.cs
index 91dd32fee1b..d517f8667f0 100644
--- a/src/OpenTelemetry/Internal/SelfDiagnosticsConfigParser.cs
+++ b/src/OpenTelemetry/Internal/SelfDiagnosticsConfigParser.cs
@@ -22,7 +22,7 @@
 
 namespace OpenTelemetry.Internal
 {
-    internal class SelfDiagnosticsConfigParser
+    internal sealed class SelfDiagnosticsConfigParser
     {
         public const string ConfigFileName = "OTEL_DIAGNOSTICS.json";
         private const int FileSizeLowerLimit = 1024;  // Lower limit for log file size in KB: 1MB
diff --git a/src/OpenTelemetry/Metrics/CompositeMetricReader.cs b/src/OpenTelemetry/Metrics/CompositeMetricReader.cs
index 4e9e5d2597f..5f778b3a836 100644
--- a/src/OpenTelemetry/Metrics/CompositeMetricReader.cs
+++ b/src/OpenTelemetry/Metrics/CompositeMetricReader.cs
@@ -179,7 +179,7 @@ public bool MoveNext()
             }
         }
 
-        internal class DoublyLinkedListNode
+        internal sealed class DoublyLinkedListNode
         {
             public readonly MetricReader Value;
 
diff --git a/src/OpenTelemetry/Metrics/ExponentialBucketHistogram.cs b/src/OpenTelemetry/Metrics/ExponentialBucketHistogram.cs
index 8fe69979b33..0f83121bea1 100644
--- a/src/OpenTelemetry/Metrics/ExponentialBucketHistogram.cs
+++ b/src/OpenTelemetry/Metrics/ExponentialBucketHistogram.cs
@@ -26,7 +26,7 @@ namespace OpenTelemetry.Metrics;
 /// identified by <c>Bucket[index] = ( base ^ index, base ^ (index + 1) ]</c>,
 /// where <c>index</c> is an integer.
 /// </summary>
-internal class ExponentialBucketHistogram
+internal sealed class ExponentialBucketHistogram
 {
     private int scale;
     private double scalingFactor; // 2 ^ scale / log(2)
diff --git a/src/OpenTelemetry/Metrics/ExponentialBucketHistogramConfiguration.cs b/src/OpenTelemetry/Metrics/ExponentialBucketHistogramConfiguration.cs
index 389b2e0e4b0..53e8510d9ff 100644
--- a/src/OpenTelemetry/Metrics/ExponentialBucketHistogramConfiguration.cs
+++ b/src/OpenTelemetry/Metrics/ExponentialBucketHistogramConfiguration.cs
@@ -19,7 +19,7 @@ namespace OpenTelemetry.Metrics;
 /// <summary>
 /// Stores configuration for a histogram metric stream with exponential bucket boundaries.
 /// </summary>
-internal class ExponentialBucketHistogramConfiguration : MetricStreamConfiguration
+internal sealed class ExponentialBucketHistogramConfiguration : MetricStreamConfiguration
 {
     /// <summary>
     /// Gets or sets the maximum number of buckets in each of the positive and negative ranges, not counting the special zero bucket.
diff --git a/src/OpenTelemetry/Metrics/StringArrayEqualityComparer.cs b/src/OpenTelemetry/Metrics/StringArrayEqualityComparer.cs
index 6a91f201eae..579325cef2a 100644
--- a/src/OpenTelemetry/Metrics/StringArrayEqualityComparer.cs
+++ b/src/OpenTelemetry/Metrics/StringArrayEqualityComparer.cs
@@ -19,7 +19,7 @@
 
 namespace OpenTelemetry.Metrics
 {
-    internal class StringArrayEqualityComparer : IEqualityComparer<string[]>
+    internal sealed class StringArrayEqualityComparer : IEqualityComparer<string[]>
     {
         public bool Equals(string[] strings1, string[] strings2)
         {
diff --git a/src/OpenTelemetry/Metrics/ThreadStaticStorage.cs b/src/OpenTelemetry/Metrics/ThreadStaticStorage.cs
index e473cfdb8af..cee643afa99 100644
--- a/src/OpenTelemetry/Metrics/ThreadStaticStorage.cs
+++ b/src/OpenTelemetry/Metrics/ThreadStaticStorage.cs
@@ -21,7 +21,7 @@
 
 namespace OpenTelemetry.Metrics
 {
-    internal class ThreadStaticStorage
+    internal sealed class ThreadStaticStorage
     {
         private const int MaxTagCacheSize = 8;
 
@@ -150,7 +150,7 @@ internal void CloneKeysAndValues(string[] inputTagKeys, object[] inputTagValues,
             }
         }
 
-        internal class TagStorage
+        internal sealed class TagStorage
         {
             // Used to split into Key sequence, Value sequence.
             internal readonly string[] TagKeys;