TIA TIA-455-56-C

ANSI APPROVED

Introduction

Intent

This method is intended to evaluate the adequacy of opticalfibers and cables to retain their structural integrity andperformance level under environmental conditions favorable for thedevelopment of fungal growth. These conditions are: high humidity,a warm atmosphere, and the presence of inorganic salts.

General effects

Organic materials commonly form an integral part of opticalfiber: for plastic cladding, for protecting the surface of a glassfiber, and for buffering. Some fibers are fabricated entirely fromvarious plastic materials. Organic materials are also commonly usedin fabricating optical cable: bufferings, filling materials,strength members, and jacketing.

Micro-organisms digest certain organic materials as a normalmetabolic process, thus degrading them and causing porosity andloss of structural integrity, even to the point of catastrophicfailure. Basic resins do not usually serve as carbon sources forgrowth of fungi. Rather it is generally other components such asplasticizers, stabilizers, colorants, lubricants, and cellulosicsthat are responsible for the actual fungus attack.

Enzymes and organic acids produced during metabolism diffuse outof their cells and on to the plastic to cause such possiblephenomena as cracking; corrosion; glass etching; hardening of cablefilling compounds; increased modulus; weight changes; dimensionalchanges; and microbending of the fiber, with a resultant increasein attenuation.

Hazards

Because of safety and toxicity considerations detailed in 1.3.3,conduct testing at a site specifically equipped for the purpose.This generally means a separate, isolated facility with the abilityto keep the test specimens within a confined area during the entiretesting and incubation period.

Similarly, all testing shall be performed by personnel trainedin microbiological laboratory techniques, sterile routines, andproper disposal of all waste solutions at the close of testing.

The reason for specifying the testing site and personnelqualifications is the potentially toxic nature of fungal spores.They have been implicated in pneumonia-like respiratory infections,ulcers of the skin, and digestive problems.

Edition:

C

Published:

07/14/2009

ANSI:

ANSI Approved

Number of Pages:

18

File Size:

1 file , 3.7 MB