Human Biology Unit 3 Report: Sunscreen SPF and UV Bead Experiment

This report details a biology experiment conducted to determine the efficacy of different SPF sunscreens (15, 30, and 50) from the same brand in protecting against UV rays. The experiment utilized UV beads, which change color upon exposure to UV light, to measure the effectiveness of each sunscreen. The methodology involved applying each sunscreen to the beads and exposing them to a UV lamp, monitoring and recording the color change over time. The results indicated that sunscreens, regardless of SPF, provided some level of protection, with higher SPF levels generally offering more protection. The SPF 50 sunscreen was found to be the most effective in preventing color change in the UV beads, supporting the hypothesis that higher SPF values correlate with increased UV protection. The report also discusses limitations such as inconsistent exposure times due to taking pictures and potential variations in UV intensity, and suggests future research directions, including investigating the specific chemical components responsible for sunscreen efficacy. The experiment concluded that the SPF 50 sunscreen provided superior protection against UV rays compared to the lower SPF sunscreens.

Introduction:
The sunscreens can be considered as chemical products that are used for the protection of the skin from the
harmful ultraviolet ray or UV rays emitted by the Sun (Mancuso et al. 2017). The increasing pollution of the
environment has caused destructions to the ozone layer, which was the natural barrier against the UV ray from
the Sun. The UV ray is considered to be a strong mutating agent. It is known to cause various skin damage
including skin cancer conditions (Hoseinzadeh et al. 2018). Sunscreens are the products that contain some
chemicals that protects the skin from the damaging effect of the UV ray (Donglikar and Deore 2016). The
chemicals either achieve it by absorbing the UV ray or they work as a physical barrier to the UV ray (Marchetti
and Karsili 2016). The sun protection factor or SPF is the measurement that describes how effective a
sunscreen is in protecting the skin against the UV ray of the Sun (Reinau et al. 2015). It is generally considered
that the higher the SPF level is, the sunscreen products are more effective in protecting the skin from the UV
ray of the Sun. A sunscreen with a high SPF level is considered to provide more extended protection to the skin
as well. In this research experiment, this consideration will be tested by the use of UV beads. UV beads are
initially colourless beads, which change their colour after they are exposed to the UV rays. The intensity of
their colour can be used as a detector of their susceptibility to the UV rays.
This paper aims for determining the efficacy of different sunscreen products from the same brand
with different SPF level in protecting the skin from the damaging effects of the UV ray by using the UV beads.
The hypothesis for the study is that the sunscreens with SPF 50 will be more effective compared to
the sunscreens with SPF 30 or SPF 15.
Materials
 20 x same coloured UV beads
 4 x petri dishes
 1 x white piece of paper
 1 x UV lamp
 1 x timer
 Nivea sunscreen SPF 15
 Nivea sunscreen SPF 30
 Nivea sunscreen SPF 50
 1 x camera (phone)
Method
1) A 1 to 7 colour scale was created on excel based on the darkest colour the UV beads reached
1. in the indoor UV light
2) 5 white UV beads without any sunscreen was placed in a petri dish
3) The petri dish was placed under the UV lamp over a white piece of paper
4) The UV lamp and timer were turned on at the same time
5) The colour change in the beads was monitored every 20 seconds for 5 minutes using a
2. stopwatch and a camera to take photos every 20 seconds by taking the dish out immediately
3. and quickly placing it back in
6) After 5 minutes, based on team judgement and the colour change every 20 seconds from
4. the photos taken was meshed into the 1 to 7 colour scale to understand the UV intake
7) 1 squirt of Nivea sunscreen SPF 15 was placed onto palm of hands
8) 5 UV beads were placed in the same palm to spread the sunscreen evenly onto the beads
9) The 5 SPF 15 UV beads were placed in a petri dish and step 3 to 6 were repeated
10) 1 squirt of Nivea sunscreen SPF 30 was placed onto palms of hands
11) 5 UV beads were placed in the same palm to spread the sunscreen evenly onto the beads
12) The 5 SPF 30 UV beads were placed in a petri dish and step 3 to 6 were repeated
13) 1 squirt of Nivea sunscreen SPF 50 was placed onto palms of hands
14) 5 UV beads were placed in the same palm to spread the sunscreen evenly onto the beads
15) The 5 SPF 30 UV beads were placed in a petri dish and step 3 to 6 were repeated
16) All steps were performed one for time for accuracy

Results:
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300
0
1
2
3
4
5
6
7
8
Trial 1- Diffrent SPF's effect on UV beads
Colour of the Beads for Different Sunscreen (Shade 1-7) Control
Colour of the Beads for Different Sunscreen (Shade 1-7) SPF 15
Colour of the Beads for Different Sunscreen (Shade 1-7) SPF 30
Colour of the Beads for Different Sunscreen (Shade 1-7) SPF 50
Exposure Time (Seconds)
Shades
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300
0
2
4
6
8
Trial 2- Diffrent SPF's effect on UV beads
Colour of the Beads for Different Sunscreen (Shade 1-7) Control
Colour of the Beads for Different Sunscreen (Shade 1-7) SPF 15
Colour of the Beads for Different Sunscreen (Shade 1-7) SPF 30
Colour of the Beads for Different Sunscreen (Shade 1-7) SPF 50
Exposure Time (Seconds)
Shades

0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300
0
1
2
3
4
5
6
7
8
Average-Diffrent SPF's effect on UV beads
Colour of the Beads for Different Sunscreen (Shade 1-7) Control
Colour of the Beads for Different Sunscreen (Shade 1-7) SPF 15
Colour of the Beads for Different Sunscreen (Shade 1-7) SPF 30
Colour of the Beads for Different Sunscreen (Shade 1-7) SPF 50
Exposure Time (Seconds)
Shades
The UV beads that did not receive an application of sunscreen, started to changed colour more quickly
compared to the beads that received an application of sunscreen. Thus it can be decided that sunscreens even
with a low SPF provides some level of protection from the UV light.
After 5 minutes of exposure of the beads to the UV light even with the application of the sunscreen with SPF
50, the beads changed colour to the shade 4 (Refer to the colour scale provided in the Appendix). Thus a
sunscreen even with a high SPF does not provide a complete protection against the UV ray.
The application of SPF 15 sunscreen on the UV beads yielded more change in the colour compared to the SPF
30 applied beads. The SPF 50 sunscreen application yielded even better result compared to the other
sunscreens. The hypothesis of the paper can be considered to be true, which suggested that SPF 50 sunscreen
should be providing a more effective protection against the UV ray compared to the sunscreens with SPF 15
and SPF 30.
Discussion:
The experiment found that the UV beads started to change colour rapidly as the time of exposure
increased. In both trials, it was found that only after 20 seconds of exposure, the UV beads quickly changed
colour. After only 2 minutes and 20 seconds of exposure, it turned into shade 7 in the second trial (Refer to the
colour scale provided in the Appendix). The beads showed the maximum susceptibility to the sunlight because
there was no protection against the UV ray was available for those beads. The test results also found that an
increase in the SPF level in the sunscreens is directly associated with a decrease in the susceptibility of the
beads to the UV ray.
The UV beads are a type of initially colourless beads that change colour after they are exposed to the
UV rays. Those beads are an effective choice to test the efficacy of the sunscreen products. The general idea
about this experiment is that the application of the sunscreens to the beads will prevent the colour change in
the beads, as those products are supposed to protect the human skin from the damaging effects of the UV ray.
The hypothesis of this report was that a sunscreen with a higher SPF level is able to provide a more effective
protection against the UV ray compared to the sunscreen with a lower SPF level. The results of the experiment
mostly supported this hypothesis. However, if the results of the SPF 15 efficacy and the SPF 30 efficacy are
compared, it can be found that sometimes SPF 15 was more effective in providing protection than SPF 30. In
case of trial 1, after 20 seconds of exposure, the beads with SPF 30, turned into shade 2, when the SPF 15
beads changed into shade 1.5 only and in trial 2, after 2 minutes of exposure, the SPF 30 beads turned into
shade 3, where the SPF 15 beads remained at 2.5 shade (Refer to the colour scale provided in the Appendix).

The results can be considered to be moderately accurate. There was a control group of beads kept
beside the experimental beads. This was to present the proper contrast between the experimental group and
the control group. However, there was some limitations in the test procedure, which should be considered and
they can also be held responsible for some error in the results. The exposure time experienced by the beads
might differ from the recorded data, since they were taken out of the exposure multiple times to take pictures.
The intensity of the UV exposure might also differ for the samples, since they were placed in the different
rooms.
This experiment was based on determining the efficacy of the sunscreen with different SPF value. In
future a study to determine the reason for why the higher efficacy of the sunscreen is associated with a higher
SPF value can be investigated. Further experiments might also be focused on determining the efficacy of the
exact chemical components in improving the efficacy of the sunscreen products.
Conclusion:
Hence, it can be concluded that from the above results that the hypothesis was true. The SPF 50
sunscreen is indeed more effective in proving an improved protection against the UV rays compared to the
sunscreens with lower SPF. The reason for coming into this conclusion was that the UV beads were found to be
less prone to colour change upon exposure into sunlight upon the application of SPF 50 sunscreen on them.

APENDIX
Observation Table for Trial 1:
Exposure Time
(Seconds)
Colour of the Beads for Different Sunscreen (Shade 1-7) Shades
Control SPF 15 SPF 30 SPF 50 1
2
3
4
5
6
7
The Colour
Scale
0 1 1 1 1
20 3.5 1 1.5 1
40 4.5 1.5 1.5 1.5
60 4.5 2 2 1.5
80 5 2.5 2 2
100 5 2.5 2.5 2
120 5.5 3 3 2
140 6 3 3 2.5
160 6.5 3.5 3 3
180 6.5 4 3.5 3
200 6.5 4 4 3.5
220 6.5 4 4 3.5
240 7 4.5 4 3.5
260 7 4.5 4 3.5
280 7 4.5 4 3.5
300 7 4.5 4 3.5
Exposure Time
(Seconds)
Colour of the Beads for Different Sunscreen (Shade 1-7) Shades
Control SPF 15 SPF 30 SPF 50 1
2
3
4
5
6
7
The Colour
Scale
0 1 1 1 1
20 2.5 1 1 1
40 3.5 1.5 1.5 1.5
60 4.5 1.5 2 1.5
80 5 2 2 2
100 6.5 2.5 2.5 2
120 6.5 2.5 3 2.5
140 7 3 3 3
160 7 3.5 3.5 3
180 7 4 3.5 3
200 7 4 3.5 3.5
220 7 4 4 3.5
240 7 4 4 3.5
260 7 4.5 4 4
280 7 4.5 4.5 4
300 7 4.5 4.5 4
Observation Table for Trial 2:

References:
Couteau, C., Diarra, H. and Coiffard, L., 2016. Effect of the product type, of the amount of applied sunscreen
product and the level of protection in the UVB range on the level of protection achieved in the UVA
range. International journal of pharmaceutics, 500(1-2), pp.210-216.
Donglikar, M.M. and Deore, S.L., 2016. Sunscreens: A review. Pharmacognosy Journals, 8(3).
Hoseinzadeh, E., Taha, P., Wei, C., Godini, H., Ashraf, G.M., Taghavi, M. and Miri, M., 2018. The impact of air
pollutants, UV exposure and geographic location on vitamin D deficiency. Food and Chemical Toxicology, 113,
pp.241-254.
Mancuso, J.B., Maruthi, R., Wang, S.Q. and Lim, H.W., 2017. Sunscreens: an update. American journal of
clinical dermatology, 18(5), pp.643-650.
Marchetti, B. and Karsili, T.N., 2016. Theoretical insights into the photo-protective mechanisms of natural
biological sunscreens: building blocks of eumelanin and pheomelanin. Physical Chemistry Chemical
Physics, 18(5), pp.3644-3658.
Olsen, C.M., Wilson, L.F., Green, A.C., Biswas, N., Loyalka, J. and Whiteman, D.C., 2017. Prevention of DNA
damage in human skin by topical sunscreens. Photodermatology, photoimmunology & photomedicine, 33(3),
pp.135-142.
Reinau, D., Osterwalder, U., Stockfleth, E. and Surber, C., 2015. The meaning and implication of sun protection
factor. Br J Dermatol, 173(5), p.1345.