This is a piece of dyed filter paper. It is a very sensitive indicator and senses the “Vinegar Syndrome” just by touching the film.
Please see the 'Resources' tab for instructions and product warnings.
Pack size: 25 strips
The colour is blue when in the bag. After taking the wanted number of testers out of the bag, squeeze the air out and close the bag carefully. Take the lid off your film can, place the indicator on the film and make a note of the time.
The reading can be done after 24 hours depending on the temperature. For cold conditions expect 2-3 days for an accurate reading. 24 hours is based on 20 degree Celsius.
Compare the reading with the colour chart and make a note of the level of acidity. If the colour changes to olive green (pH 4,6) you have reached the critical autocatalytic point, which is the point where you should consider separating it from the rest of the collection and begin to duplicate.
If the indicator has not reacted within 24 hours nothing is critical.
If you leave the indicator in the open air it will fade.
Warning: Close contact with severely degraded acetate and nitrate films (touching and sniffing) may be a health hazard. Acetic acid and other acidic products emitted by degraded film have been known to produce contact burns, skin and mucous membrane irritations, and other physiological effects. Protective gloves and adequate ventilation are strongly recommended for handling degraded films.