diff --git a/src/components/DataTable/DataTableBody.tsx b/src/components/DataTable/DataTableBody.tsx
index c9ae761..3e513c7 100644
--- a/src/components/DataTable/DataTableBody.tsx
+++ b/src/components/DataTable/DataTableBody.tsx
@@ -5,7 +5,7 @@ import { cn } from '#utils';
 
 import { DataTableEmptyState } from './DataTableEmptyState.tsx';
 import { useDataTableHandle } from './hooks.ts';
-import { flexRender } from './utils.tsx';
+import { flexRender, getSizeVariableName } from './utils.tsx';
 
 import type { DataTableContentProps } from './types.ts';
 
@@ -45,7 +45,7 @@ export const DataTableBody: FC<
           >
             {row.getVisibleCells().map((cell) => {
               const style: CSSProperties = {
-                width: `calc(var(--col-${cell.column.id}-size) * 1px)`
+                width: `calc(var(${getSizeVariableName('col', cell.column.id)}) * 1px)`
               };
               if (cell.column.getIsPinned() === 'left') {
                 style.left = `${cell.column.getStart('left')}px`;
diff --git a/src/components/DataTable/DataTableHead.tsx b/src/components/DataTable/DataTableHead.tsx
index 38dcfcb..0c4c362 100644
--- a/src/components/DataTable/DataTableHead.tsx
+++ b/src/components/DataTable/DataTableHead.tsx
@@ -2,7 +2,7 @@ import type { CSSProperties } from 'react';
 
 import { ACTIONS_COLUMN_ID } from './constants.ts';
 import { useDataTableHandle } from './hooks.ts';
-import { flexRender } from './utils.tsx';
+import { flexRender, getSizeVariableName } from './utils.tsx';
 
 export const DataTableHead = () => {
   const headerGroups = useDataTableHandle('headerGroups');
@@ -16,7 +16,7 @@ export const DataTableHead = () => {
             const style: CSSProperties = {
               // TODO - add more robust solution - should be able to block centering also - also set correct typing
               justifyContent: header.column.columnDef.meta?.centered ? 'center' : 'start',
-              width: `calc(var(--header-${header?.id}-size) * 1px)`
+              width: `calc(var(${getSizeVariableName('header', header.id)}) * 1px)`
             };
             if (header.column.getIsPinned() === 'left') {
               style.left = `${header.column.getStart('left')}px`;
diff --git a/src/components/DataTable/__tests__/DataTable.spec.tsx b/src/components/DataTable/__tests__/DataTable.spec.tsx
index b9d34cb..105325b 100644
--- a/src/components/DataTable/__tests__/DataTable.spec.tsx
+++ b/src/components/DataTable/__tests__/DataTable.spec.tsx
@@ -61,6 +61,23 @@ describe('DataTable', () => {
     expect(root).toHaveStyle({ backgroundColor: 'blue' });
     expect(root.style.getPropertyValue('--data-table-accent')).toBe('red');
   });
+  it('should set valid CSS variables for a column whose ID contains spaces', () => {
+    render(
+      <DataTable
+        columns={[{ accessorFn: (row) => row.email, header: 'Email', id: 'Email Address (work)' }, ...columns.slice(2)]}
+        data={data}
+      />
+    );
+    const style = screen.getByTestId('data-table-head').parentElement!.getAttribute('style')!;
+    const variableNames = style
+      .split(';')
+      .map((declaration) => declaration.split(':')[0]!.trim())
+      .filter((name) => name.endsWith('-size'));
+    expect(variableNames).toHaveLength(4);
+    for (const name of variableNames) {
+      expect(name).toMatch(/^--[a-zA-Z0-9_-]+$/);
+    }
+  });
   it('should search', async () => {
     render(<DataTable columns={columns} data={data} />);
     const searchBar = screen.getByTestId('data-table-search-bar').querySelector('input')!;
diff --git a/src/components/DataTable/__tests__/utils.spec.ts b/src/components/DataTable/__tests__/utils.spec.ts
new file mode 100644
index 0000000..7706da2
--- /dev/null
+++ b/src/components/DataTable/__tests__/utils.spec.ts
@@ -0,0 +1,17 @@
+import { describe, expect, it } from 'vitest';
+
+import { getSizeVariableName } from '../utils.tsx';
+
+describe('getSizeVariableName', () => {
+  it('should not change an ID that contains only letters, digits, and hyphens', () => {
+    expect(getSizeVariableName('col', 'first-name1')).toBe('--col-first-name1-size');
+    expect(getSizeVariableName('header', 'email')).toBe('--header-email-size');
+  });
+  it('should return a valid CSS variable name for an ID that contains spaces', () => {
+    expect(getSizeVariableName('col', 'First Name')).toMatch(/^--[a-zA-Z0-9_-]+$/);
+  });
+  it('should return different names for IDs that differ only in special characters', () => {
+    const names = ['a b', 'a_b', 'a.b', 'a_20_b', 'ab'].map((id) => getSizeVariableName('col', id));
+    expect(new Set(names).size).toBe(names.length);
+  });
+});
diff --git a/src/components/DataTable/store.ts b/src/components/DataTable/store.ts
index 6c84bcb..57aa124 100644
--- a/src/components/DataTable/store.ts
+++ b/src/components/DataTable/store.ts
@@ -17,6 +17,7 @@ import {
   defineMemoizedHandle,
   getColumnPinningWithActions,
   getColumnsWithActions,
+  getSizeVariableName,
   getTanstackTableState
 } from './utils.tsx';
 
@@ -63,8 +64,8 @@ export function createDataTableStore<T>(params: DataTableStoreParams<T>) {
           style.visibility = 'visible';
         }
         for (const header of headers) {
-          style[`--header-${header.id}-size`] = header.getSize();
-          style[`--col-${header.column.id}-size`] = header.column.getSize();
+          style[getSizeVariableName('header', header.id)] = header.getSize();
+          style[getSizeVariableName('col', header.column.id)] = header.column.getSize();
         }
         return { style };
       });
diff --git a/src/components/DataTable/utils.tsx b/src/components/DataTable/utils.tsx
index eb2d706..5a6a91b 100644
--- a/src/components/DataTable/utils.tsx
+++ b/src/components/DataTable/utils.tsx
@@ -172,6 +172,20 @@ function getTanstackTableState<T>({ initialState, rowActions }: DataTableStorePa
   return state;
 }
 
+/**
+ * Returns the name of the CSS variable that holds the size of a header or column.
+ *
+ * An ID can contain characters that are not valid in a CSS variable name (e.g., a space). Each
+ * character other than an ASCII letter, a digit, or a hyphen is replaced by its code point between
+ * underscores. Because the underscore itself is replaced, two different IDs cannot give the same name.
+ */
+function getSizeVariableName(kind: 'col' | 'header', id: string): `--${string}` {
+  const encodedId = Array.from(id, (char) => {
+    return /[a-zA-Z0-9-]/.test(char) ? char : `_${char.codePointAt(0)!.toString(16)}_`;
+  }).join('');
+  return `--${kind}-${encodedId}-size`;
+}
+
 function isReactComponent<TProps>(component: unknown): component is ComponentType<TProps> {
   return typeof component === 'function';
 }
@@ -183,5 +197,6 @@ export {
   flexRender,
   getColumnPinningWithActions,
   getColumnsWithActions,
+  getSizeVariableName,
   getTanstackTableState
 };