The Effects of

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The Effects of Calcium Hypochlorite and
Polyhexamethylene Biguanide on Swimsuit Fabrics
By Kaitlyn Pendleton
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• Introduction
• Pool sanitation is an important issue in the
  world today because of bacterial outbreaks. Many
  pool sanitizers, but few are completely safe for
  swimmers and their bathing suits.
• This experiment was conducted to test the
  bleaching effects of the most widely used
  sanitizers on the market, chlorine and
  polyhexamethylene biguanide.
• Chlorine is known to be a harsh, oxidizing
  chemical that causes fading (similar to laundry
  bleach).
• Polyhexamethylene biguanide, on the other hand,
  is not an oxidizer and, therefore, should not
  harm the fabric.

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• Materials Methods
• Set-up 5 pumps-2 calcium hypochlorite (2 ppm,
  10 ppm), 2 PHMB (40 ppm, 120 ppm) and one tap
  water control.
• 3 squares of fabric submerged in each bucket with
  an aquarium pump for 48 hours then extracted and
  data for color count, elasticity, and luminous
  flux were taken.

Picture by Kaitlyn Pendleton
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Materials Methods

• Guardex Super Chlorinator (calcium hypochlorite)
  and Baquacil Algistat (PHMB) were used.
• Buckets were treated as a normal pool would be
  and balanced according to the Association of Pool
  and Spa Professionals Standards.

Picture by Kaitlyn Pendleton
Picture by Kaitlyn Pendleton
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• Parameters Measured
• Color count Pictures of fabric were taken and
  analyzed by a black to white histogram in Adobe
  Photoshop. Color count at level 34 was measured
  for all. Pictures taken under

• same fluorescent lighting, had a white balance of
  400, an F-stop of F4.4, and a shutter speed of
  1/30.
• Luminous Flux Fabric laid on white light box and
  flux meter used to measure amount of light
  escaping.
• Elasticity A weight (with 4.727 N of force) and
  clamps were attached to fabric. The length of the
  stretched fabric was measured. Hookes Law
  (kFs) was used to calculate the elasticity
  constant.

Picture by Kaitlyn Pendleton
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• Results
• A one-way ANOVA analyzed the data for each
  parameter but only calcium hypochlorite at 10 ppm
  affected the color count and luminous flux of the
  nylon swimsuit fabric significantly.
• P-values Color count ---6.18 x 10-19 , luminous
  flux---7.21 x 10-10 , elasticity---0.344.

• Pictures taken for color count showed the extreme
  difference, too. Fabric exposed to chlorine
  appeared gray and mottled against the dark black
  of all the others.

Picture by Kaitlyn Pendleton
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Results

• Figure 1 compares the means of all sanitizers.
  One can see the extreme difference in calcium
  hypochlorite (10 ppm) from the others.

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Results

• Figure 2 shows how the mean of luminous flux for
  calcium hypochlorite (10 ppm) is much higher than
  all the other sanitizers means.

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Discussion Conclusions

• As the fabric faded and lost its black pixel
  count the luminous flux level increased because
  more light could escape through the lighter
  colored fabric.
• A change in elasticity may not have been observed
  because the fabric would need more exposure time
  to the chemical for this effect to be visible.
• The extreme differences in the means of luminous
  flux, black pixel count, and the visible fading
  for calcium hypochlorite (10 ppm) indicate that
  high levels of chlorine do cause damage to nylon
  swimsuit fabric color while polyhexamethylene
  biguanide does not.

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Discussion Conclusions
www.pendletonpools.com

• These findings do support the original research
  hypothesis.
• Other studies referenced in this experiment
  showed that PHMB may not only keep your bathing
  suit looking nice, but also keep your pool
  cleaner than chlorine.

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Questions?