Aerosol Test Methods…

This aerosol guide contents various test methods including incoming component to be used for the Intermediate – compatibility, functionality, and weight loss studies.

 These tests are very important 

I highly recommend with my experiences of Pennwalt (isotron) Phillips Petroleum (LPG) and L’Oreal. 

These tests are for new aerosol products which to be launch.  And for any changes are made in current formula.  Such as, perfume and different chemicals.    

The solvent used in formula should be tested for moisture present in the solvent, and propellant or secure certificate of Analysis from vendor. 

These tests are as follow:  

The first step of testing is to check incoming component to be used for the product.

 1. Containers  2.   Valves     3.   Actuators 

Also included the safety precautions while testing incoming components and finished product for compatibility, functionality, and weight loss studies.  All the tests to be carried out in an explosion proof exhaust hood and oven.   All the tools used must be spark proof.

The chemist must wear safety gears to protect He/herself.

Most important instruments required to do incoming component testing. Compatibility, functionality and wait lost, gauges, scale, pin gauges.



  1. Buckle and burst containers.

Altek Hydrostatic Tester & CNC KUHNKE Hydrostatic Burst Tester #ABT-1000-0008021401

  1. Waco instrument.

SENCON-mA tester

  1. Fisher-scope – to measure the thickness of internal varnish.

SENCON STRAND gauge (test plates from various lining suppliers required to calibrate unit)

  1. Other instrument such as the curl, bottom concave, and others.

(Boxal-2 or Boxal-3 for Contact Height), Curl Thickness Gauge made by Starrett

  1. Ruler-mm – secure from the vendor.

This ruler will give measurements of height and diameter.  Also provides maximum total fill capacity.



Adhesion of spray button
Resistance of coating to alcohol
Resistance of coating to CuSO4
Porosity of the internal varnish
Disruption voltage (aluminum cup with standard anodizing)
Disruption voltage (aluminum cup with specific anodizing)
Seal and operation
Additional vapor tape
Internal restriction*
Tear off force of dip tube
Dip tube length under gasket
Springs/balls oxidation (standard steel)
Springs/balls oxidation (particular steel)
Spray button airflow rate
Pouch seal
Emergent height
Stem internal diameter
Pouch height under gasket
Diameter of rolled pouch
Diameter of the insert orifice
Control of the drawing dimensions
Rupture of bracelets
Resistance of seams

  Aluminum aerosol cans

Adherence of internal coating
Reticulation of internal coating
Resistance to internal pressure
Thickness of metal
Insulating power of internal coating / aluminum cans
Weight of container
Total height
Diameter base of locking groove
Exterior Diameter
Shoulder height
Control of the drawing dimensions
Contact height
Interior diameter of the collar
Exterior diameter of the collar
Cup fitment height
Ageing in light – UV/Window
Legibility and Quality of printed of barcode
Barcode dimensions
Legibility and Quality of printed Data Matrix Code
Resistance of artwork to acetone, alcohol, bulk, manual and mechanical rubbing, adhesive tape, sand, grid pattern test, barrel test, linear abrasion, water bath
Thickness of internal coating
Thickness of internal coating (Epoxy phenolic)
Measurement of the deformation of aluminum cans
Surfacing angles
Residual thickness
Bending of the base
Analysis of liquid residues
Valve-can seal
Micro count (incoming components)
Quality of varnish




Microscope test.

Pins gauge test.

Infra-red (or substitute to identified stem gasket or depend on the certification of analysis by vendor)

Dip tube puller test. 




 Formulator must check moisture present in the solvents and propellants by using Karl Fischer instrument.   The moister in the solvent and propellants are very important and critical.  

The solubility of the other chemicals used in the formula should be soluble in the solvent.

Once the bench formula is ready, transfer in to 6oz glass bottle and secure tightly than remaining solution as per formula transfer into plastic coted bottle and crimp 20mm valve than inject propellant percentage required.

Now put 6oz. bottle and plastic coted bottle into explosion proof hot oven at 45 deg. C for 48 hours.  After 48 hours take out both the bottle from the oven and put it on working bench to stabilized till room temperature and observe if there is any changes.

Check pH from 6oz of class bottle, color and odor.

   Compatibility, Functionality And weight Loss:


 The component required for these test methods:

  1. Containers: 74 units.
  2. Valves and actuators: 74 units.

After testing all the chemicals, prepare your batch as per requirements on net weight total liters/gallons.  Formulator must keep in mind that 7.5% head space is required by law for the final aerosol formula.

 Compatibility:   20 Units:

  1. 10 units in up position.
  2. 10 units in inverted position.
    1. At 45 deg. C for 60 days.
  3. 10 units in up position.
    1. At room temperature for 60 days.
  4. 10 units in up position.
    1. At room temperature for 1 year, two years and four years.
    2. Two virgin units with valve and actuators without crimping for 60 days at 45 deg. C – control.

Functionality:  24 units:  weekly functionality 

  1. 12 units up position.
  2. 12 units inverted position.

At 45 dig C for 60 days.  BUT every week, night before take these containers and put it in exhaust hood over-night to stabilize to room temperature.

Very important:   Net weight in the container to be divided by 8.   These grams to be spray once a week.   (exp.  if net weight is 100 grams/8 = 12.5 gram to be spray out from each container which are store upper and inverted position.

Theses process to be applying for the both position containers and re-stored in hot oven for the next week. (This process will last for 8 weeks.)

Observations:  During spray, if you find irregular spry or not spray due to clogging of valve, actuator, or irregular pattern.

Investigate particular container:  Remove the propellant after puncture tiny hole in the cup. Collect the concentrate from the can and examine of separation of the solution or body/stem the opening holes are clogs and take a valve apart and examine stem gasket and spring.  Remaining 23 cans continue testing for following weeks. If you find clogging again than stop the testing.

  1. 10 units up position.

    At room temperature spray every days:

    Net weight 100 grams/60 days (1.2 grams) spray per day per can.

    If you find    Irregular or unusual spray patters than stop testing and      

    Investigate why?


   Weight Loss:  Compatibility 

All the units as described in compatibility must be weigh and mark its’ weight on containers.  Also mark showing up or inverted position.

After 60 days of 45 deg. C and room temperature re-weight and make a note of any weight loss from initial weight.

This includes the units which are stored in hot oven for 60 days and stored at room temperature for compatibility.

After 60 days compatibility remove units from hot oven and transfer units into exhaust hood until stabilized till room temperature Including the 24 units’ compatibility at room temperature.

When all the units are stabilized in room temperature make a very tiny hole using spark proof ice pick in the mounting cup.

This process must be done under explosion proof exhaust hood.  Leave all these units over night under the hood to allow propellant to escape over-night.

Next day make two or three bigger hole in the mounting cup and collect the solution of all units in to one large beaker.

When cans are empty, rinse with water than cut each can using mettle cutter or electric bled saw.

After cutting all the units clean it with running water and keep it in hot oven to dry.

Exam each can for any unusual appearance, such as detaining, Corrosion, any formation of bubbles, peeling of internal lining.  These include unusual sign in bottom of the mounting cup.

Check the concentrate which is remove from these units for any color change, any particles from the concentrate.

Also check the ph. or any unusual reaction.  

INVESTIGATE:   If there is a weight loss —- why?

The containers which has loss of weight should be in hot water bath 55deg. C.

If you notice any bubbles from crimp, stem, pedestal or other parts of the cans than remove can from the water bath, put in exhaust hood, make a tiny hole and allow the gas to escape.

Follow the same process above for investigation.


  1. Check the total gross weight of 12 containers.
  2. Check vapor pressure at room temp and 55deg.C and 20deg C every one hour by QA.
  3. Check spray rate of the total 12 units gms /sec at 20deg C every one hour by QA.
  4. Check spray pattern at 20deg C.
  5. Check net weight of each container (12 units) by totally spray out in the explosion proof hood.
  6. Crimp diameter depth and stem height (every 30min) two units after hot water bath.


This test is required by labeling act regulation 

These above test to be carried out every one year on 12 containers.

Aerosol containers – Fished Goods Testing.

Appearance The aim of this method is the detection of appearance defects in the Finished Goods. N/A
Functionality The aim of this method is to detect defects that might be noticeable to consumers from the first look at store up until its use. N/A
Resistance to the pressure at 50°C The aim of this method is to assure that each individual aerosol is resistant to a pressure at least at 50°C as required

by law.


– A manometer with a measuring range from 0 to 16 bars and a resolution of 0.01 bars, and with tip adaptors for the different types of valves.

Manometer and tips should be such that the dead volume is as small as possible (maxi 0.2 ml).

– A thermostat-controlled water bath at T ± 1°C, where T is the temperature of the water bath on the production line. The water bath should be fitted with a system to keep the aerosols immersed.

– A stopwatch.

Fill weight The aim of this method is to assure that a lot of Finished Goods conforms to the legislation on filling. A 1/100th g scale
Crimping (Crimping diameter, difference between 2 measurements, external diameter of cap, crimping height, stem height, emergent height) The objective of this method is to assure the correct crimping of valves in order

to guarantee:

– Seal of the finished product.

– A non-deterioration of the internal protective layer for the aerosol.

Please Refer to Valve Manufacturer/Suppliers
Restitution rate The objectives of this test are:

– To evaluate the amount of product that consumer actually will be able to use.

– To detect defects that might be noticeable by consumers during the product evacuation.


Test must be conducted by simulating as closely as possible the normal consumer’s gestures.


A 1/100th g scale


Control of draining (Purge test) The aim of this method is to verify that the draining operation is thoroughly carried out and that there is no gas remains in the dip tube. 1. In case of a draining operation with water:

– A balance with a precision of hundredth of gram.

2. In case of a draining operation with nitrogen,

– A manometer with a measuring ranges 0 to 16, with a resolution to the tenth and tip adaptors for the different types of valves (class 0.6 manometer).

Draining (foam) The aim of this method is to verify that after filling and packing operations the aerosol can be emptied completely and that the foam is dispensed correctly. N/A
Vacuum check (aerosol cans) The objective of this method is to verify that the vacuum operation was done correctly.

Placing aerosol in vacuum is done after crimping of the valve and is required to avoid the effects of a gust of air at the beginning of use the aerosol and also allowing the best consistency of flow and pressure.

A vacuum meter with a resolution to the hundredth and a precision of 0.02 bar


Resistance of lot number to bulk, water, tearing. Dry adhesion The objective of this method is to verify that the lot number is legible as required

by law.

The following tests can be performed:

– Test with adhesive tape.

– Dry rubbing test.

– Water resistance test.

– Resistance to contained product.

Quality of barcodes The aim of this method is to ensure that barcodes (EAN 8, EAN 13, UPC-A and UPC-E) comply in their structure and could be read with any type of scanning equipment around the world. Any scanner that can provide readings of Legibility, Decodability, Print Quality, Magnification Factor and Margins Dimension.
Resistance of labels This method consists in ensuring acceptable resistance of labels placed on the Finished


Humidity Chamber
Resistance to falling (dangerous goods) The aerosols belong to the family of dangerous goods (flammable gas).

The aim of this method is to ensure that packaging is strong enough to resist the usual stresses that occur during transport whether transported in pallets or as single packs.

1.     A Climatic Chamber to condition finished goods.

2.     A drop tester to drop a shipper.

Resistance to vibrations The aim of this test is to validate the damaging

effect of vibration and shock produced during

the transportation, storage and handling of a finished product.

3.     A Climatic Chamber to condition finished goods.

4.     A Vibration Table with following characteristics:

–       Amplitude test displacement: 25.4 mm/1”

–       Fixed low frequency vibrations range: 3 – 5 Hz.

–       Constant vertical acceleration: 0.5 – 1.0 g.

5.     Test time: 60 minutes (rotating carton 90 0 after 30 minutes).



These specifications are recommended from my 50 years of experiences of the aerosol industry. 

  1. Internal varnish in the containers
  1. Epoxy Phenolic: 10 to 25 microns
  2. PAM : 6 to 21 microns.
  1. Containers curl:  Boxal 3.
  1. Vapor pressures at 130 F.
  2. DOT 2N – 0 to 140 psig.
  3. DOT 2P – 141 to 160 psig.
  4. DOT 2Q – 161 to 180 psig.
  1. Crimp:  Finished product
  1. Diameter: 069 +/- 0.004 inches

         Depth:  0.209 +/-0.004 inches 

  1. Stem height:   No specs – height should be able to accommodate the actuator opening height.



  1. Chemist /Technician Must be properly trained,
  2. Now smoking, NO cell phone
  3. Must wear Safety Glasses with side shield
  4. Must wear cotton cloth- No synthetic Clothing
  5. Must Be Trained to Use Fire Extinguisher or fire-fighting equipment
  6. Must not wear shoes with steel heel
  7. The gas cylinders must be grounded properly
  8. Explosion Proof Exhaust Hood must be used
  9. Water bath temperature should not be exceed 55C
  10. Use tong and Face shield during removing cans from 55 c water bath.

        And all cans must pass the 55 c water bath test

  1. Must calculate the minimum 20 % Head Space. (80% Full)