diff --git a/index.ts b/index.ts
index 9c02526..b1b66a0 100644
--- a/index.ts
+++ b/index.ts
@@ -1082,7 +1082,7 @@ export class RFC5424 extends RFC {
     super();
     options = options || {};
     this.hostname = options.hostname || os.hostname();
-    this.applicationName = options.applicationName || '';
+    this.applicationName = options.applicationName || '-';
     this.timestamp = options.timestamp !== false;
     this.timestampMS = options.timestampMS !== false;
     this.timestampTZ = options.timestampTZ !== false;
@@ -1154,8 +1154,8 @@ export class RFC5424 extends RFC {
    *    message
    * @param {string} [options.pid='-'] - The process id of the service sending
    *    this message
-   * @param {string[]} [options.structuredData] - An array of structure
-   *    data strings conforming to the IETF/IANA defined SD-IDs or IANA
+   * @param {object} [options.structuredData] - An object of structure
+   *    data objects conforming to the IETF/IANA defined SD-IDs or IANA
    *    registered SMI Network Management Private Enterprise Code SD-ID
    *    conforming to the format
    *    [name@<private enterprise number> parameter=value]
@@ -1181,7 +1181,6 @@ export class RFC5424 extends RFC {
     let applicationName = options.applicationName || this.applicationName;
     let pid = options.pid || '-';
     let id = options.id || '-';
-    let msgStructuredData = options.msgStructuredData || [];
     let fmtMsg = ''; // Formated Syslog message string var
     const newLine = '\n';
     const newLineRegEx = /(\r|\n|(\r\n))/;
@@ -1251,26 +1250,7 @@ export class RFC5424 extends RFC {
       }
     }
     // Build Structured Data string
-    let structuredData = '-';
-    const sdElementCount = msgStructuredData.length;
-    if (sdElementCount > 0) {
-      let sdElementNames = [];
-      let sdElements = [];
-      const sdElementNameRegEx = /(\[)(\S*)(\s|\])/;
-      // Loop to drop duplicates of the same SD Element name
-      for (let elementIndex = 0;
-        elementIndex < sdElementCount;
-        elementIndex++) {
-        let elementName =
-          msgStructuredData[elementIndex]
-            .match(sdElementNameRegEx)[2];
-        if (!sdElementNames.includes(elementName)) {
-          sdElementNames.push(elementName);
-          sdElements.push(msgStructuredData[elementIndex]);
-        }
-      }
-      structuredData = sdElements.join('');
-    }
+    const structuredData = RFC5424.buildStructuredData(options.structuredData);
     // Build the message
     fmtMsg = '<' + pri + '>';
     fmtMsg += '1'; // Version number
@@ -1288,6 +1268,28 @@ export class RFC5424 extends RFC {
     fmtMsg += newLine;
     return fmtMsg;
   }
+  static buildStructuredData(data) {
+    // Build Structured Data string
+    let result;
+    if (data) {
+      result = Object.entries(data).map(([sdId, sdParam]) => {
+        return '[' + [
+          sdId,
+          ...Object.entries(sdParam)
+            .map(([name, value]) =>
+              `${name}="${RFC5424.escapeParamValue(value)}"`
+            ),
+        ].join(' ') + ']';
+      }).join('');
+    }
+    return result || '-';
+  }
+  static escapeParamValue(value) {
+    return String(value)
+      .replace(/\\/g, '\\\\')
+      .replace(/"/g, '\\\"')
+      .replace(/]/g, '\\]');
+  }
   /**
    * send a RFC5424 formatted message.  Returns a promise with the formatted
    *    message that was sent.  If no server connection was defined when the
diff --git a/tests/syslog.test.js b/tests/syslog.test.js
index 47997fe..76072c1 100644
--- a/tests/syslog.test.js
+++ b/tests/syslog.test.js
@@ -336,10 +336,9 @@ describe('RFC5424 Class Tests', () => {
     });
     result = rfc5424.buildMessage('hello', {
       msgColor: 30,
-      msgStructuredData: [
-        '[ourSDID@32473 test=test]',
-        '[ourSDID@32473 test=test]'
-      ]
+      structuredData: {
+        'ourSDID@32473': { test: 'test' }
+      }
     });
     resultMsg = /<190>1 \d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{1,3} /;
     expect(result).toMatch(resultMsg);
@@ -417,6 +416,23 @@ describe('RFC5424 Class Tests', () => {
     });
     expect(result).toMatch(/^<190>1 \d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{1,3}[\+\-]\d{2}:\d{2} hostname applicationName - - - BOMhello\n$/);
   });
+  test('RFC5424 BuildMessage with structredData option', () => {
+    const rfc5424 = new SyslogPro.RFC5424();
+    const result = rfc5424.buildMessage('hello', {
+      structuredData: {
+        "hi@32473": {
+          foo: 1,
+          bar: 2
+        },
+        escape: {
+          quoteCharacter: '"',
+          backslack: '\\',
+          closingBrace: ']'
+        }
+      }
+    });
+    expect(result).toMatch(/^<190>1 \S+ \S+ - - - \[hi@32473 foo="1" bar="2"\]\[escape quoteCharacter="\\"" backslack="\\\\" closingBrace="\\]"\] BOMhello\n$/);
+  });
   test('RFC5424 SetColors', () => {
     let rfc5424 = new SyslogPro.RFC5424();
     const result = rfc5424.setColor({