diff --git a/cara/models.py b/cara/models.py
index a5c63b2e..481074cd 100644
--- a/cara/models.py
+++ b/cara/models.py
@@ -478,7 +478,7 @@ class Mask:
     η_inhale: _VectorisedFloat
 
     #: Global factor applied to filtration efficiency of masks when exhaling.
-    factor_exhale: _VectorisedFloat = 1.
+    factor_exhale: float = 1.
 
     #: Pre-populated examples of Masks.
     types: typing.ClassVar[typing.Dict[str, "Mask"]]
diff --git a/cara/tests/test_infected_population.py b/cara/tests/test_infected_population.py
index 8ef94729..7acef7f7 100644
--- a/cara/tests/test_infected_population.py
+++ b/cara/tests/test_infected_population.py
@@ -8,7 +8,6 @@ import cara.models
     "override_params", [
         {'viral_load_in_sputum': np.array([5e8, 1e9])},
         {'quantum_infectious_dose': np.array([50, 20])},
-        {'factor_exhale': np.array([0.92, 0.95])},
         {'exhalation_rate': np.array([0.75, 0.81])},
     ]
 )
@@ -16,7 +15,6 @@ def test_infected_population_vectorisation(override_params):
     defaults = {
         'viral_load_in_sputum': 1e9,
         'quantum_infectious_dose': 50,
-        'factor_exhale': 0.95,
         'exhalation_rate': 0.75,
     }
     defaults.update(override_params)
@@ -26,7 +24,7 @@ def test_infected_population_vectorisation(override_params):
             number=1,
             presence=office_hours,
             mask=cara.models.Mask(
-                factor_exhale=defaults['factor_exhale'],
+                factor_exhale=0.95,
                 η_inhale=0.3,
             ),
             activity=cara.models.Activity(
@@ -37,9 +35,7 @@ def test_infected_population_vectorisation(override_params):
                 viral_load_in_sputum=defaults['viral_load_in_sputum'],
                 quantum_infectious_dose=defaults['quantum_infectious_dose'],
             ),
-            expiration=cara.models.Expiration(
-                ejection_factor=(0.084, 0.009, 0.003, 0.002),
-        ),
+            expiration=cara.models.Expiration((1., 0., 0.)),
     )
     emission_rate = infected.emission_rate(10)
     assert isinstance(emission_rate, np.ndarray)