diff --git a/src/app/modules/colors/components/mix-editor/mix-editor.component.html b/src/app/modules/colors/components/mix-editor/mix-editor.component.html
index 0378e9d..3c5f35e 100644
--- a/src/app/modules/colors/components/mix-editor/mix-editor.component.html
+++ b/src/app/modules/colors/components/mix-editor/mix-editor.component.html
@@ -46,8 +46,8 @@
       <th mat-header-cell *matHeaderCellDef>Produit</th>
       <td mat-cell *matCellDef="let mixMaterial">
         <mat-form-field *ngIf="materials">
-          <mat-select [(ngModel)]="mixMaterial.materialId">
-            <mat-option *ngFor="let material of materials"
+          <mat-select #select [(ngModel)]="mixMaterial.materialId" [value]="mixMaterial.materialId">
+            <mat-option *ngFor="let material of getAvailableMaterials(select)"
                         [value]="material.id">{{material.name}}</mat-option>
           </mat-select>
         </mat-form-field>
@@ -99,7 +99,7 @@
 </ng-template>
 
 <cre-confirm-box
-  *ngIf="editionMode"
+  *ngIf="editionMode && mix"
   #deleteConfirmBox
   message="Voulez-vous vraiment supprimer le mélange {{mix.mixType.name}} de la recette {{recipe.company.name}} - {{recipe.name}}"
   (confirm)="delete()">
diff --git a/src/app/modules/colors/components/mix-editor/mix-editor.component.ts b/src/app/modules/colors/components/mix-editor/mix-editor.component.ts
index e3e212d..6420169 100644
--- a/src/app/modules/colors/components/mix-editor/mix-editor.component.ts
+++ b/src/app/modules/colors/components/mix-editor/mix-editor.component.ts
@@ -16,6 +16,7 @@ import {ConfirmBoxComponent} from '../../../shared/components/confirm-box/confir
 import {AccountService} from '../../../accounts/services/account.service'
 import {EmployeePermission} from '../../../shared/model/employee'
 import {ErrorService} from '../../../shared/service/error.service'
+import {MatSelect} from '@angular/material/select'
 
 @Component({
   selector: 'cre-mix-editor',
@@ -131,6 +132,10 @@ export class MixEditorComponent extends SubscribingComponent {
     return id ? this.materials.filter(m => m.id === id)[0] : null
   }
 
+  getAvailableMaterials(selector: MatSelect): Material[] {
+    return this.materials.filter(m => selector.value === m.id || this.mixMaterials.filter(mm => mm.materialId === m.id).length === 0)
+  }
+
   get canDeleteMix() {
     return this.accountService.hasPermission(EmployeePermission.REMOVE_RECIPE)
   }
diff --git a/src/app/modules/employees/pages/edit/edit.component.ts b/src/app/modules/employees/pages/edit/edit.component.ts
index ad45c80..27d8478 100644
--- a/src/app/modules/employees/pages/edit/edit.component.ts
+++ b/src/app/modules/employees/pages/edit/edit.component.ts
@@ -97,7 +97,7 @@ export class EditComponent extends ErrorHandlingComponent {
   }
 
   get idControl(): FormControl {
-    this._idControl = this.lazyControl(this._idControl, () => new FormControl(this.employee.id, Validators.compose([Validators.required, Validators.pattern(new RegExp('^[0-9]+$')), Validators.min(0)])))
+    this._idControl = this.lazyControl(this._idControl, () => new FormControl({value: this.employee.id, disabled: true}, Validators.compose([Validators.required, Validators.pattern(new RegExp('^[0-9]+$')), Validators.min(0)])))
     return this._idControl
   }