Is the #ColorRun hazardous to your health?

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The Color RunTM is in Newcastle this weekend, and I’ll be running the #happiest5k for the third time. It’s a great event with a warm and friendly atmosphere, and because it’s so family-friendly and kids are encouraged to #runwithmum, one of my young daughters will be running alongside me. There’s just one thing that I’m not sure of about this whole event, and that’s whether the “color”, which is the name they give to the coloured corn-starch (which is what we Australian’s call corn-flour) thrown at you throughout the run, is hazardous to your health.

When occupational hygienists are unsure whether workers are being over-exposed, they can perform what’s known as an “exposure assessment” to determine if the hazard presents a significant risk to health….so that’s what I plan to do!

The first step in the exposure assessment process involves information gathering. The Color RunTM website tells me that the colour is made from corn-starch and natural plant based food dyes…with the added bonus of being gluten free. That’s fine, except that corn-starch and natural plant based food dyes aren’t typically thrown into the air at you and then inhaled.

I contacted the Color RunTM and asked them for a copy of the Safety Data Sheet. I also told them that my daughter has asthma and asked if there was any advice against doing the run in her case. “Color Support” were quick to get back to me with the following information (sans SDS and reference to the question on asthma):

Thank you for your email! The color is a cornstarch base and is dyed with food grade dyes. It is even Gluten free. 🙂  Here is a list of the ingredients in our color: Blue Thank – FD and C Blue 1 Lake Low, Melojel Starch. Green – FD and C Blue 1 Lake Low, FD and C Yellow Lake 36-42 PCT, Melojel Starch. Pink – FD and C Red 40 Lake 36-42PCT, Melojel Starch. Yellow – FD and C Yellow 5 lake 36-42 PC, Melojel Starch. Our color has gone through extensive testing. In the Material Safety Data it says there could be some irritation since the color can form dust, but in all of the testing it states that there is nothing The MSD sheets show the Potential Health effects are as follows: Oral Exposure – Swallowing this material is not likely to be harmful. Dermal Exposure – Unlikely to cause skin irritation or injury. Inhalation Exposure – This material is a dust or may produce dust. Breathing small amount of this material is not likely to be harmful. Eye Exposure – Dust can cause eye irritation Symptoms may include stinging, tearing redness and swelling of eyes. Symptoms of Exposure – No data Other Health Effects – The material can form dust, which may cause skin or mucous membrane irritation. Symptoms may include redness, burning, and swelling. Although they may cause respiratory tract irritation, nuisance dusts do not form scar tissue or affect the structure of air spaces in the lungs. Their effects on the tissues are potentially reversible.

Whilst I like the smily face touch in their email, according to their information the dust may be irritating, but breathing in a small amount of material is not likely to be harmful. Have a look at the picture below. Do you think this meets the definition of a “small amount of material”?

I think the health risks might be a bit understated, hence the reason for performing an exposure assessment. As a preventative measure, our youngest daughter (the asthmatic) probably won’t run with us this weekend…and if she does, then she won’t be taken into the color throw at the end which is where the above picture was taken.

I then did a bit of background research on the health effects of corn-flour in general to understand the health impact: It’s relatively harmless when you buy it in the packet at Coles and use it to thicken your gravy, but when you get it as a dust in the air it causes irritation of the respiratory tract which can range from allergy-type symptoms, coughing, wheezing, shortness of breath, eye irritation, through to asthma. Some people are what’s known as “sensitised”, which means that they are more likely to show some of the above symptoms when they are exposed to lower levels. Sensitisation can occur from previous exposures that may have happened many years after their initial exposure.

The next step in this exposure assessment is to define what’s termed, “Similar Exposure Groups” or SEGs. These are groups of workers that are expected to have the same general exposure because of the similarity and frequency of the tasks they perform, the materials and processes which they work, and the similarity of the way they perform the tasks. In this case, my SEG will be “runners” participating in the Newcastle Color RunTM. As part of this, I also need to identify the exposure scenarios, which in this case, will be focused only on the potential inhalation of corn flour to color runners.

I then need to make a judgement about the exposure, which in this case, based on my experience doing two previous Color RunsTM, I’m going to call the exposures “uncertain”. I need to also decide how I’m going to determine if it’s hazardous. In this case, as it’s not practical to sample all the color runners, I’m going to select a sub-set of runners and collect enough samples to at least perform inferential statistics…so I’m going to sample exposure from at least six runners. I do have a slight limitation here, as these statistics rely on the samples being randomly collected, and I plan on sampling a targeted group of people (including 3 hygienists and 3 willing participants). However, we are all at different levels of fitness and won’t all run at the same pace or at the same time, so I’m trying my best to make this randomised.

I then need to decide on an exposure standard (ie: a limit) for the assessment, and also a metric to use to compare the data to that standard. I’m going to use the value recommended by Safe Work Australia for grain dust (oats, wheat, and barley) of 4mg/m3. That value was designed to reduce the effect of respiratory symptoms, but it would not be sufficient to prevent sensitisation or occupational asthma in the long-term. However, as the exposure period is expected to last for around an hour, and I’m going to assume that participants (well, us at least) are not exposed on an ongoing basis, I think that this value is fit for purpose.

I also need to set the methodology and sampling parameters for the measurement approach. I’ll be measuring inhalable dust via IOM samplers in accordance with AS3640 (2009) with the measurement period starting from when we first line up at the “start line” and finishing just before we leave the venue of the Newcastle Jockey Club.

I’m going to use a simplified approach and go with the method recommended by the AIHA and use the Exposure Rating Categorisation System which is based on the estimate of the 95th percentile relative to the exposure standard. In every-day language, this just means that I want 95% of my data to be below the recommended limit.

If this were a work site in NSW, then I’d want to see 95% of the data below half of that limit, as anything over half of the limit typically means that the process may not be under reasonable control to protect the workers. Further to that, you already know that exposure standards are not a dividing line between safe and unsafe, they are designed to protect most workers, but not all workers…so you need some leeway in there also.

The next step is to put in some preliminary temporary controls to prevent over exposure. During the last Color RunTM my daughter wore goggles to prevent the colour going into her eyes, she wore a bandana around her face to prevent breathing in the dust (hygienists everywhere are rolling their eyes as they no how ineffective these are!), and we don’t go through the voluntary “air blown cleaning zone” which is promoted so you are, “totally good for the drive home”. We’ll use the same controls this time also.


It will be a few weeks until the results are in, but I’ll keep you posted on the outcome. If it turns out that doing the Color RunTM poses a risk of developing harmful health effects due to dust exposure, then sadly this weekend will be the last Color RunTM we will attend. That will be a pretty sad thing, as my daughter absolutely loves it. It’s currently on par with the One Direction concert at this point…yes it’s that sad…so fingers crossed!