2 Comment On Cylinderized Phosphine Gas Products :

Cylinderized phosphine gas should not be subject to ecological and environmental fate risk assessment because use in burrows is not permitte d. Aqua tic and terrestrial exposure to cylinderized phosphine gas is not expected . None of the reported incidents with phosphine gas

involved ECO 2 FUME ® or VAPORPH 3 OS ®

.

EFED response:

Aquatic and terrestrial exposure is expected for any phosphine produ ct, including cylinderized

gas products, once phosphine is released from fumigated structures. Limited aquatic exposure is expected as noted in the problem formulation. Therefore, EFED is mainly concerned with terrestrial exposures.

Comments on Ecologica l Effects Data Gaps:

The three ecotoxicology studies are not needed (avian acute inhalation, honey bee acute

inhalation

, and terrestrial plant vapor phase study). During aeration, p hosphine will be diluted and will degrade rapidly in the atmosphere. M on itoring data around fumigation sites indicates that phosphine air concentrations are low, transient (less than two hours), and rarely present more

than 3

- 15 feet from the fumigated structure . M onitoring that is required for protection of workers and bysta nders is equally protective of non

- target plants and animals. The requirement for terrestrial plant toxicity is not relevant since phosphine below the soil surface is quickly absorbed and degraded. T he likelihood of avian and honeybee exposure to phosphi ne gas in the environment at an atmospheric concentration high enough to produce toxicity is almost non

existent

.

EFED response:

Monitoring data as well as modeling predictions are used to estimate exposure to phosphine gas (i.e., what concentration of phosphine gas is expected around fumigated structures)

. Such data

are useful for worker protection only because the concentration/duration of exposure that is

harmful to human health is known from other studies ( effects data) that can be compared to the monitoring data. The requested studies generate effects data for birds, insects, and plants for comparison with the monitoring data and modeling predictions

. Birds, insects, and terrestrial plants could be exposed to peak con centrations of phosphine emitted around the exterior of fumigated structures (also plant roots in treated burrows). Phosphine gas is extremely toxic to animals by inhalation and can cause harmful effects even over short exposure periods. Therefore, EFED considers th e s e effects data to have high value in reducing uncertainty of risk.

Comments on Use and Usage Information :

Under Use Sites , information for phosphine has not been fully included. In addition to the uses listed, Cytec's products are permitted to be used on a variety of stored fresh fruit and vegetable

commodities.3 In the Summary of Usage , although it is true that use of phosphine products has increased as

met hyl bromide has been phased out and the use of cylinderized phosphine has in creased because it allows for better control of targeted fumigations, the figures produced by BEAD do not appear to be correct. Table 3 of the supporting BEAD chemical profile in the docket lists use in 2009 at 164,241lb phosphine from aluminum phosphide u se, 7,9571b phosphine from magnesium phosphide use and 263,667 lb phosphine, presumably from use of EC O 2 FUME and VAPORPHOS. These reported values suggest that 1.6x more cylinderized phosphine is sold than aluminum and magnesium phosphide combined. As repor ted in the information summary provided to EPA on June 3, 2013, estimated phosphine from Cytec's cylinderized phosphine products was much l ess than that amount. Perhaps DPR inadvertently counted a cylinder of

ECO 2 FUME as 100% phosphine when in fact it cons ists of 2% phosphine on a w/w basis.

The f ormulation t ype should be corrected to read "Phosphine is formulated and cylinderized as a liquid pressurized gas ”.

EFED response:

EFED will make these corrections in the ecological risk assessment document

, as warranted

. The Agency will verify the usage corrections in paragraph two of the registrant comments ( above ) and make corrections to the BEAD chemical profile if appropriate

.