Diisocyanates (isocyanates), including methylene diphenyl diisocyanate (MDI), are the primary reactive components of spray polyurethane foam (SPF) insulation.
They are potent immune sensitizers and a leading cause of occupational asthma.
Skin exposure to isocyanates may lead to both irritant and allergic contact dermatitis and possibly contribute to systemic sensitization.
More than sufficient evidence exists to justify the use of protective garments to minimize skin contact with aerosolized and raw isocyanate containing materials during SPF applications.
Studies evaluating the permeation of protective garments following exposure to SPF insulation do not currently exist.
To conduct permeation testing under controlled conditions to assess the effectiveness of common protective gloves and coveralls during SPF applications using realistic SPF product formulations.
Five common disposable garment materials [disposable latex gloves (0.
Tyvek coveralls (0.
These materials were cut into small pieces and assembled into a permeation test cell system and coated with a two-part slow-rise spray polyurethane foam insulation.
Glass fiber filters (GFF) pretreated with 1-(9-anthracenylmethyl)piperazine) (MAP) were used underneath the garment to collect permeating isocyanates.
GFF filters were collected at predetermined test intervals between 0.
For each garment material, we assessed (i) the cumulative concentration of total isocyanate, including phenyl isocyanate and three MDI isomers, that effectively permeated the material over the test time; (ii) estimated breakthrough detection time, average permeation rate, and standardized breakthrough time; from which (iii) recommendations were developed for the use of similar protective garments following contamination by two-component spray polyurethane foam systems and the limitations of such protective garments were identified.
Each type of protective garment material demonstrated an average permeation rate well below the ASTM method F-739 standardized breakthrough rate threshold of 100.
Disposable latex gloves displayed the greatest total isocyanate permeation rate (4.
The Tyvek coverall demonstrated a greater average rate of isocyanate permeation than the polypropylene coveralls.
Typical isocyanate loading was in the range of 900 to 15,000 ng MDI/cm2.
Permeation test data collected during this study indicated that each type of protective garment evaluated, provided a considerable level of protection (i.
SPF insulation mixture.
Nitrile gloves and polypropylene coveralls demonstrated the lowest rate of permeation and the lowest cumulative permeation of total isocyanate for each garment type.Full Article