How can PHP be used to store configuration data in INI format and what are the security considerations?

To store configuration data in INI format using PHP, you can use the `parse_ini_file()` function to read an INI file and retrieve its contents as an associative array. This allows you to easily access and modify configuration settings in your PHP application. However, it's important to consider security implications when storing sensitive data in an INI file, such as database credentials or API keys. Make sure to restrict access to the INI file by placing it outside the web root directory or using appropriate file permissions.

```php
// Read configuration data from an INI file
$config = parse_ini_file('config.ini');

// Access configuration settings
$databaseHost = $config['database_host'];
$databaseUser = $config['database_user'];
$databasePass = $config['database_pass'];
```
Make sure to replace 'config.ini' with the path to your actual configuration file.