diff --git a/resources/home/dnanexus/generate_workbook/tests/test_utils.py b/resources/home/dnanexus/generate_workbook/tests/test_utils.py
index 6c436cb5..3821e1c9 100644
--- a/resources/home/dnanexus/generate_workbook/tests/test_utils.py
+++ b/resources/home/dnanexus/generate_workbook/tests/test_utils.py
@@ -11,10 +11,14 @@
 def test_is_numeric():
     """
     Tests that all forms of numerical value are correctly identified as
-    being numeric
+    being numeric, and things we don't want to are treat as non-numeric
     """
-    numeric_values = ['5', '5.5', '-0.1', '1e-5']
-    non_numeric_values = ['5,6', '5, 6', '.', '3/4', ]
+    numeric_values = ['5', '5.5', '-0.1', '1e-5', '.1']
+
+    non_numeric_values = [
+        '5,6', '5, 6', '.', '3/4', '1..1', '1.1.1', '5ee5', '123e', '-e1',
+        '.e1', 'e1', '1.1.1', '01', '0001'
+    ]
 
     assert all([is_numeric(x) for x in numeric_values]), (
         'some numeric values do not properly evaluate to being numeric'
diff --git a/resources/home/dnanexus/generate_workbook/utils/utils.py b/resources/home/dnanexus/generate_workbook/utils/utils.py
index e325548e..f793bc66 100644
--- a/resources/home/dnanexus/generate_workbook/utils/utils.py
+++ b/resources/home/dnanexus/generate_workbook/utils/utils.py
@@ -1,3 +1,6 @@
+from re import L
+
+
 def is_numeric(value:str) -> bool:
     """
     Returns true if given value is in some form numeric
@@ -12,5 +15,17 @@ def is_numeric(value:str) -> bool:
     bool
         True if value can be numeric
     """
-    return str(value).lstrip('-').replace('.', '').replace(
-        'e-', '', 1).replace('e', '').isdigit()
\ No newline at end of file
+    try:
+        if str(value)[0] == '0' and not str(value)[1] == '.':
+            # catch things such as 01 which aren't real numbers
+            return False
+    except Exception:
+        # could raise lots of errors (i.e IndexErrors from slicing)
+        # lazily catch all and continue
+        pass
+
+    try:
+        float(value)
+        return True
+    except ValueError:
+        return False