TIA TIA-455-56-B

ANSI APPROVED

Introduction

Intent

This method is intended to evaluate the adequacy of optical fibers andcables to retain theirstructural integrity and performance level under environmentalconditions favorable for thedevelopment of fungal growth. These conditions are: high humidity, awarm atmosphere, and thepresence of inorganic salts.

General effects

Organic materials commonly form an integral part of optical fiber: forplastic cladding, forprotecting the surface of a glass fiber, and for buffering. Somefibers are fabricated entirelyfrom various plastic materials. Organic materials are also commonlyused in fabricating opticalcable: bufferings, filling materials, strength members, and jacketing.

Micro-organisms digest certain organic materials as a normal metabolicprocess, thus degrading themand causing porosity and loss of structural integrity, even to thepoint of catastrophic failure.Basic resins do not usually serve as carbon sources for growth offungi. Rather it is generallyother components such as plasticizers, stabilizers, colorants,lubricants, and cellulosics that areresponsible for the actual fungus attack.

Enzymes and organic acids produced during metabolism diffuse out oftheir cells and on to theplastic to cause such possible phenomena as cracking; corrosion; glassetching; hardening of cablefilling compounds; increased modulus; weight changes; dimensionalchanges; and microbending of thefiber, with a resultant increase in attenuation.

Hazards

Because of safety and toxicity considerations detailed in 1.3.3,conduct testing at a sitespecifically equipped for the purpose. This generally means aseparate, isolated facility with theability to keep the test specimens within a confined area during theentire testing and incubationperiod.

Similarly, all testing shall be performed by personnel trained inmicrobiological laboratorytechniques, sterile routines, and proper disposal of all wastesolutions at the close of testing.

The reason for specifying the testing site and personnelqualifications is the potentially toxicnature of fungal spores. They have been implicated in pneumonia-likerespiratory infections, ulcersof the skin, and digestive problems.

Edition:

B

Published:

01/12/1995

ANSI:

ANSI Approved

Number of Pages:

16

File Size:

1 file , 610 KB