2/05/03

Relationship between formaldehyde in the air and formaldehyde in the water

QUESTION
Is there a relationship between the concentration of formaldehyde in the air contained in the desiccators, and formaldehyde concentration caught in the water?

ANSWER
Gas “dissolves” in water in proportion to the temperature of the water and gas.  Gas bumps around in the air until a molecule hits the water surface and either bounces off or dissolves.  If enough Fy was present in the air after some time equilibrium would form …this is in common with all gas mixtures above liquids…. But in this test Fy is at too low a concentration for this to occur …so if you double the time …you will more or less double the result.  BUT after a day or two Fy will start to decompose…. So a sort of equilibrium may occur where the rate of absorption into the water equals the rate of breakdown.

2/05/03

Sample surface area

QUESTION
Is it important to keep the same sample surface area to be able to compare result of products with different thicknesses?

ANSWER
Yes - to be sure of your results it pays to keep all variables the same … It may be OK to alter the surface area …… but a rule of testing is keep everything you can constant …this is because proving that it does not matter once …does not prove the rule …so unless you have a big budget to prove surface are does not matter ….then keep it the same.

2/05/03

Sample volume and air volume in desicators

QUESTION
Is it important to have approximately the same sample volumes to keep the same air volumes in each of the desiccators during testing of different product thicknesses?

ANSWER
Maybe ……BUT this method is not an accurate way to measure Fy …..it is only approximate ……. If you wish to run trials of your own ….. to see how good your product is …then I recommend you use the 40L chamber and follow that method exactly.   For sales however you are at the mercy of the standards and the standards say that your product is plywood and that means you must follow the plywood standard.

2/05/03

Formaldehyde concentration  vs desiccator air volume

QUESTION
Does the formaldehyde concentration in the desiccator air depend on desiccator air volume?

ANSWER
I have trialled different sizes of desiccators and bigger volume didn’t equal lower results.

2/05/03

Influence of evaporation on desiccator tests

QUESTION
Does the fact that the total amount of water during the test is decreased, (evaporated and absorbed by the samples) have an influence on the evaluation of the test?

ANSWER
Hydrolysis of large formaldehyde based molecules produces Fy gas and therefore the higher the moisture content the higher the emission. That is why we pre-condition at 65%/20C in most standards. 

Many standards for all sorts of test work are less than ideal …… a better standard for FE is the chamber method EN717-1 which requires a standard RH and temperature and the FE is measured each day until a constant emission is reached …typically labs charge this test at 3K a time …so it is no good for day to day use.  For day to day testing we often use methods, which are less than perfect…. The JD test is one …but we are stuck with it.  Since correlations have been done comparing JD with the Standard chambers …… the theory is that the limits have been set to allow for the deficiencies in the method.  Since the temperature is fixed the water loss (and gain by the sample) should be the same each time and therefore should not matter …since the same would have occurred during the correlations from which the limits were set.

2/05/03

Saturation point of formaldehyde in water

QUESTION
What is the maximum saturation point of formaldehyde in water? 

ANSWER
The higher the temperature the greater the water holding of air. For data click here.

2/05/03

Molecular weight of formaldehyde

QUESTION
Is formaldehyde heavier than air?

ANSWER
Formaldehyde in air forms a gas mixture …so it does not drop out and form a layer on the bottom of the chamber!

The Fy molecule  is COH2 and therefore has a molecular weight of 30.  Air is 78% N2 molecular weight is 28 and 20% O2 molecular weight 32.  SO I guess you could say that Fy is about average.

2/05/03

How does formaldehyde get into the water?

QUESTION
How does formaldehyde get into the water?

ANSWER
Any gas above a liquid dissolves in the liquid.  Water is polar and acts differently to most other liquids ……but this does not really matter …….a molecule of gas hits the water and is dissolved in the water.

14/04/03

Correct version of the Japanese Desiccator Test

QUESTION
Which is the current version of the Japanese Desiccator test

ANSWER
The new version of the Japanese Desiccator test is Standard No. JIS A 1460:2001, Title: Building boards Determination of formaldehyde emission -- Desiccator method.  JIS A 5905-2003 Title Fibreboards  Draft (At Present 1994 still current) now has the specifications but not the testing methodology. For an English Version use AS/NZS 4266:16 2001(Int), this method complies  with the JISA1460 method and is the current method for Australia and New  Zealand

14/04/03

Recent history of the Japanese Desiccator test.

QUESTION
What is the recent History of the Japanese Desiccator Test

ANSWER
JISA1460 and AS/NZS4266:16 were produced from JANS 16 ... .the harmonisation method, written by TimberTest, for the Australian, New  Zealand and Japanese standards harmonisation committee. The JISA1460 standard has been altered a little from the harmonisation method but if you test according to AS/NZS4266:16 you will still comply with JISA1460.

14/04/03

Where to find information on the Japanese Desiccator test

QUESTION
How do we obtain a copy of the Japanese Desiccator Test

ANSWER
To find the Australian Standards and Japanese Standards web sites ...go to the Links  section of this site.  Both Australian standards and Japanese Standards

14/04/03

Correct methods - Japanese desiccator test.

QUESTION
How do we know which method to use for with Australia, New Zealand and Japan

ANSWER
For exports to Japan you must use

The new version of the Japanese Desiccator test which is Standard No. JIS A 1460:2001, Title: Building boards Determination of formaldehyde emission -- Desiccator method.

There is also a Japanese Chamber method specified by the Japanese MLIT - Ministry Land Transport and Infostructure Standard No. JIS A 1901:2003 Title Determination of the emission of volatile organic compounds and aldehydes for building products -- Small chamber method

This method is specified for use for testing produced from non JIS/JAS companies exporting to Japan.

JIS A 5905-2003 Title Fibreboards  Draft (At Present 1994 still current) now has the specifications but not the testing methodology.

For the Australian and New Zealand markets use AS/NZS4266:16 2001(Int)

14/04/03

Ensuring that you are getting the correct results with Japanese desiccator tests

QUESTION
How can we be sure we are getting the correct result when we do Japanese Desiccator Testing

ANSWER
Every three months LabCheck run round robins.  Because the testing of emissions is requires an exact sequence of conditioning and testing, the only way you can be sure that your results are correct is to take part in regular round robin testing.  The LabCheck system is confidential and simple to use.  For more information go to the Labcheck website

8/04/03

ISO 17025

QUESTION
What is  ISO 17025?

ANSWER
ISO/IEC 17025 - (General Requirements for the Competence of Calibration and Testing Laboratories).  The standard was published in 1999 and replaces ISO Guide 25 and EN 45001.It  was developed to provide guidance to laboratories on both quality management and the technical requirements for proper operation.  ISO 17025 is considered to be the technical compliment to ISO 9000.  Therefore, any organization that reaches ISO 17025 accreditation also meets ISO 9000 requirements.. ISO 9000 standards are generic and applicable to any type of organisation whereas the ISO 17025 requirements are specific to testing and calibration laboratories.  Technical competence of personnel, behavior of staff, test and calibration procedures, participation in proficiency testing, and contents of test reports and certificates are all part of the accreditation process. The standard addresses laboratory accreditation and acceptance of test data worldwide with all participating countries being required to accept the test results performed by accredited members.

14/03/03

VOC Regulations in USA, What are the VOC limits for wood product

QUESTION
In USA what are the VOC limits for wood products.

ANSWER
For VOC emissions from wood products, there are no Federal, state or city mandatory emission requirements.  In the U.S., all VOC emission requirements are established in bid specifications, usually for office furniture. Some Federal agencies, state governments, and city governments have established VOC emission requirements for wood products used in the construction of public buildings, but these requirements are not universally mandatory.

Most states do not have VOC emission standards.  There is no residential VOC standard in the U.S.

03/03/03

USA Formaldehyde Emission Regulations, Specifications for panels

QUESTION
What are the specifications for panel products in USA

ANSWER
The primary requirement for panels is the HUD (Housing and Urban Development) standard which regulates formaldehyde emissions for panels used in manufactured housing.  The test requirement is waived for phenolic-bonded panels due to historical results that show PF bonded panel formaldehyde emissions are well below the stated limits.  

The limits are 0.30 ppm for industrial applications and 0.30 ppm for residential applications.  The level is established based on ASTM E1333 (large chamber) and quality assurance is based on ASTM D5582 (desiccator).  In recent years, a "dynamic chamber" method has been developed, ASTM D6007.

26/02/03

Internal Bond, Low Results or High Standard Deviation

QUESTION
Why are my laboratory results low or why do I have a high standard deviation.

ANSWER
Assuming that you are participating in LabCheck or some other trial system and are sure that your results are low due to your laboratory and not due to production problems, then the following check-list may help.

1. Check the calibration of instrument.
2. Check the rate of loading by stopwatch and ruler.
3. Ensure you have swivels top and bottom.
4. After carrying out an IB test, remove the sample from the IB block and check that the glue covers the whole surface of the sample.

If this fails to resolve the problem:

1. Arrange for a check laboratory to glue 20 samples to your IB blocks.
2. Return ten glued samples to your laboratory, the check laboratory keeps the other ten.
3. On the same day test 10 of these samples at your own laboratory and 10 at the check laboratory (both laboratories using the same rate of loading).
4. If both laboratories now get a similar average result the problem lies with the gluing method used at your laboratory or with the glue itself.

26/02/03

Formaldehyde Testing, Dish size

QUESTION
The crystallising dish we have is 110mm inside diameter, not 115 as specified in the standards.  Will this make much difference.

ANSWER
The amount of formaldehyde which transfers into the water is a function of the surface area of the water.  Since the surface area is less for the 110mm diameter dish the formaldehyde which dissolves in the water will be less, and therefore you will get an incorrect low result.

The correct dishes may be obtained in Japan.

20/02/03

Formaldehyde decay, When should samples be measured

QUESTION
How long after production should a sample be tested for Formaldehyde Emission (FE)?

ANSWER
All the FE methods require the product is tested"as received" at the laboratory, (although there may be a certain prescribed conditioning phase to be conducted by the laboratory).

Since FE gets less with time, the age of the sample effects the result.  However the purchaser is only concerned with the FE at the time of purchase.

For this reason most production companies have the test laboratory measure and graph some FE reduction curves. This is done by testing the product every 2 days for 10 days then every week for 3 months.  (This would normally show exponential decay.)

Using the decay graph as a guide the company should decide on a time after production to carry out all testing.  Typically the testing is conducted between 2 and 4 weeks after production.