Peanut allergies are a growing problem among school-age children. Schools are struggling to cope with balancing the safety of children with peanut allergies with the freedom of non-allergic children. What is really necessary to clean up peanut residue for children with peanut allergies? How far do schools really need to go?
Luckily, there has actually been research done on the most effective way to clean up peanut proteins from surfaces, hands, and mouths, and on the potential for allergic reactions from airborne particles of peanut protein.
Cleaning Tables and Desks
Once peanut butter has gotten on a table, is it possible to get it all off? Do you need to use anything special to clean it with?
A recent study found that common household cleaners could easily remove all traces of peanut protein from tables.
Researchers smeared a teaspoon of peanut butter over a square foot of clean table. They then washed it off and tested the clean table for the presence of peanut protein. They found that these common cleaners left no detectable trace of peanut protein:
- 409 Spray Cleaner
- Target Cleaner With Bleach
- Lysol Wipes
- Plain water
Washing with dish soap left a tiny but detectable trace of peanut protein on one-third of the tables. (This finding is strange, since soap should clean better than plain water.) Researchers believe that the level of peanut protein left behind by the dish soap (40-140 ul/ml) was below the minimum threshold for someone with peanut allergy to experience a reaction.
What kind of hand washing is effective for removing peanut residue? Is hand sanitizer okay if you are not near a sink?
Plain old soap and water are the most effective tools for removing peanut residue from hands. If you are away from water, use baby wipes instead of hand sanitizer. Hand sanitizer does not remove peanut protein.
Researchers coated the hands of study participants with a teaspoon of peanut butter and then asked them to wash their hands normally with soap and water, with hand wipes, and with antibacterial hand sanitizer. Participants were told to wash their hands normally, like they always do.
Researchers found that these hand washing methods left no detectable trace of peanut protein:
- Liquid soap and water
- Bar soap and water
- Wet Ones wipes
- Tidy Tykes wipes
However, washing with plain water or using liquid hand sanitizer did not effectively remove peanut proteins. Researchers were able to find significant levels of peanut protein on all 12 study participants after washing with plain water or using hand sanitizer.
Is washing out students' mouths necessary? It is even effective?
Rinsing or washing out your mouth does not reduce the amount of peanut protein present in your saliva.
Researchers had study participants eat two tablespoons of peanut butter, and then measured the levels of peanut protein in their saliva for several hours afterward. Researchers found that these activities did NOT lower the level of peanut protein present in saliva below levels that could potentially cause a reaction in someone with a peanut allergy:
- Rinsing mouth out with water
- Brushing teeth
- Chewing gum
- Waiting an hour
The only thing that did seem to lower peanut protein levels was eating a peanut-free meal and waiting several hours. Teenagers with peanut allergies who have begun dating should be counseled on the need for open communication about their allergy with their dates, because it is possible to have a severe allergic reaction from kissing someone who has recently eaten peanuts.
Airborne Peanut Particles
If you have a peanut allergy, can you have an allergic reaction just from being in a room with peanuts?
Several studies have found that cooking or heating peanuts can release allergens into the air that can cause reactions. In general, the smell of peanuts or peanut butter is not enough to provoke a reaction, nor is breathing near someone who is eating peanuts or peanut butter.
Researchers simulated different settings in which peanuts are consumed, including a school cafeteria, an airplane, and a sporting event. Study participants wore personal air monitors while they sat next to open jars of peanut butter, ate peanut-butter sandwiches, and opened multiple packages of peanuts and ate them in an enclosed area. In the last study participants shelled and ate peanuts, then threw the shells on the floor and walked around on them. In none of these cases were the researchers able to detect any airborne peanut protein.
Another study found that 30 children with documented allergies to peanuts did not have any reaction after breathing with a cup of peanut butter held one foot from their nose over a 10-minute period.
However, yet another study found four cases of children who had allergic reactions to peanuts in the classroom in which a teacher or other adult was watching the child and knew that the child did not touch or eat the peanuts. In three of these cases, peanut butter was being heated up in the classroom. In the final case, a child was sitting next to 15 preschoolers who were eating peanut butter crackers.
Maloney, J.M., et al. Peanut allergen exposure through saliva: Assessment and interventions to reduce exposure Journal of Allergy and Clinical Immunology, Volume 118, Issue 3, September 2006, Pages 719-724
Maloney, J.M., et al. Peanut allergen exposure through kissing (saliva): Assessment and intervention. Journal of Allergy and Clinical Immunology, Volume 117, Issue 2, Supplement 1, February 2006, Page S34
Perry, T. et al. Distribution of peanut allergen in the environment Journal of Allergy and Clinical Immunology, Volume 113, Issue 5, May 2004, Pages 973-976
Sicherer, S.H., et al. The US peanut and tree nut allergy registry: characteristics of reactions in schools and day care, J Pediatr 138 (2001), pp. 560-565
Simonte, S J et al. Relevance of casual contact with peanut butter in children with peanut allergy, J Allergy Clin Immunol 112 (2003), pp. 180-182.