ROOF CLEANING WITH CHLORINE (SODIUM HYPOCHLORITE)
Chemical Roof Cleaning Companies face government opposition.
The Occupational Health and Safety Administration (OSHA) who once recommended using Chlorine (Sodium Hypochlorite) to treat mold was the first federal agency to stop recommending the use of Chlorine in mold remediation. Subsequently, The Environmental Protection Agency wrote-out/edited their guide (EPA 402-k-02-003) to exclude the use of bleach as a mold clean-up agent.
Chlorine Gas was used as a chemical warfare agent in the 1st World War, Chlorine gas is highly toxic and can kill, Chlorine gas is released when Chlorine is mixed with ammonia which is present in a large number of domestic cleaning products.
Roof cleaning contractors who use Chlorine generally do not rinse the mixture off the roof, the concentrated residues that drip from the roof after dew or light rain will kill plants (see picture below).
These mature plants were protected by tarps during the cleaning process, the damage to the plants happened as a result of the residue of concentrated chemicals that dripped off the roof several days after the contractor had finished cleaning the roof.
Chris Tucker of Apple Roof Cleaning is not ashamed of being called a "Chlorine Cowboy" he maintains that chemical roof cleaning with Chlorine is perfectly safe for plants. We have spoken to many customers who totally disagree, having had their plants destroyed by this type of chemical cleaning process, they are convinced that they will no longer have chlorine used on their roof. (It is interesting to note that in the field of horticulture there are no commercial weed killers which contain Chlorine).
Why Does Chlorine Kill Plants?
Chlorine damages organic cells by releasing free oxygen which combines with plant cell proteins causing them to denature. Because the hypochlorite ion forms when such compounds as sodium hypochlorite (NaoCl; bleach) contact the organic materials which make up the cell membrane, it is also likely that the lipoprotein structure is disrupted, causing cytoplasm leakage and killing the cell.
Chemical Roof Cleaning Contractors are recognizing that customers are becoming increasingly Anti-Chlorine and are finding new ways to market Chlorine promoting it as 100% Biodegradeable. The term Biodegradeable does not mean that it is safe, virtually every chemical is bio-degradeable, even radioactive isotopes are biodegradeable (after 100,00 years!!!) but you would not consider pouring radioactive isotopes on your roof.
Guidelines For Consumers
Our guidelines to consumers are as follows, if the contractor says he is using Sodium Hypochlorite then that is Chlorine and in which case it is highly corrosive and has the potential to damage plants and metal fittings including gutters and AC units (as the bove photograph aptly demonstrates).
If the contractor says they will protect your plants during the course of the chemical cleaning process then look at the photograph above, the residue that comes off the roof cannot be contained by tarps it will simply run off into the ground. Some contractors advocate plugging or bagging the gutter downspout all this will do is contain the caustic chemical mix in the gutter and downspout eventually it will have to be released into the ground.
The KC Group of Florida is against the use of Chlorine for the purposes of tiled roof cleaning. The http://www.clean4life.net website aims to increase awareness about the damaging effects of Chlorine on the environment.