是不是DBHELPER里的属性和方法最好不用STATIC类型的？

基本我只是连接1个数据库，1个连接字符串，我的方法都是静态的（网上找的一个DBHELPER，写的很清爽，所以用了），是不是用户并发多了就会出错？using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;/// <summary>
/// dbl 的摘要说明
/// </summary>
public class dbl
{
public dbl()
{
//
// TODO: 在此处添加构造函数逻辑
//
}
    private static SqlConnection connection;
    public static SqlConnection Connection//静态属性
    {
        get
        {
                        
            string connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
            if (connection == null)
            {
                connection = new SqlConnection(connectionString);
                connection.Open();
            }
            else if (connection.State == System.Data.ConnectionState.Closed)
            {
                connection.Open();
            }
            else if (connection.State == System.Data.ConnectionState.Broken)
            {
                connection.Close();
                connection.Open();
            }
            return connection;
        }
    }
    public static int ExecuteCommand(string safeSql)//静态方法
    {
        SqlCommand cmd = new SqlCommand(safeSql, Connection);
        try
        {
            int result = cmd.ExecuteNonQuery();
            return result;
        }
        catch
        {
            return -1;
        }
        finally
        {
            connection.Close();
        }
    }
高手指点下，谢谢