SMTL Dressings Datacard

Product Name: Silastic foam
Classification Name: Dressing Cavity Wound, Silicone Foam BP
Manufacturer: Dow Corning, distributed by Calmic Medical Division


Silastic Foam dressing is a two-part, room-temperature vulcanising foam, produced from a poly(dimethylsiloxane) base and a stannous octanoate catalyst, which react together to form a soft, pliable, slightly absorbent and non-adherent pale beige foam, which can be used to replace gauze packs or other dressings for certain defined applications. When cured, the final volume of the foam `stent' is approximately four times that of the original mixture.


The use of Silastic Foam is indicated in the management of a variety of acute granulating and post-surgical wounds. It has been found to be particularly valuable after surgical excision of a pilonidal sinus, and in the management of other perianal and perineal wounds after surgery for cancer or inflammatory bowel disease. Its successful use has also been reported in the treatment of oro-cutaneous fistulae, hidradenitis suppurativa, sacral and trochanteric decubitus ulcers, and cases of abdominal wall breakdown.


Silastic Foam should not be introduced into deep narrow wounds that might contain constrictions or hidden pockets or sinuses, as these could result in small pieces of the cured foam becoming detached and remaining undetected in the wound, leading to problems later on.

Concerns over the safety of Silastic foam have been investigated in depth by the manufacturers and have been shown to be groundless.

Method of use

Although the dressing is easy to use, it does differ significantly from traditional materials, and requires particular attention to the manufacture of the foam stent. The base and catalyst must be mixed in the ratio of 100:6 - full details of the technique involved are given on the insert that comes with each pack.

The exact volumes of the two components used will depend upon the size of the wound, but for convenience, 10 ml of base and 0.6 ml of catalyst are frequently used. These volumes are taken up from the bulk container in appropriately sized syringes, transferred to a suitable mixing vessel, and stirred thoroughly for 15 seconds, before the resulting mixture is poured into the wound. If the foam is to be used after surgical excision, it is usual to pack the wound with a suitable gauze dressing for the first 2-3 days to produce a firm-walled cavity before instituting treatment with Silastic Foam.

Frequency of Change

The dressing should be removed at least once a day and the wound cleansed with normal saline. For larger perineal or perianal wounds, the patient may be given a salt bath, where appropriate. The stent should be soaked in a 0.5% aqueous solution of chlorhexidine for 5-10 minutes, and rinsed thoroughly under running water, before being replaced into the wound. Antiseptic solutions containing cetrimide are not recommended. Each dressing may be used for up to a week - or even longer, depending upon circumstances - but as healing progresses, successively smaller stents will need to be produced.


The catalyst used in the production of Silastic Foam is an irritant, and should not be allowed to come into contact with skin or eyes.


20 g kit (for ward use)

500 g kit


Silastic Foam should be stored in a cool place. The shelf life is three years from the date of manufacture.


1. Wood RAB, Foam elastomer dressing in the management of open granulating wounds: experience with 250 patients, Br. J. Surg., 1977, 64, 554-557.

2. Macfie J., et al., The management of the open perineal wound using a foam elastomer: a prospective clinical trial, Br. J. Surg., 1980, 67, 85-89.

3. Whitakar RH, et al., Silastic foam during hypospadias surgery, Ann. R. Coll. Surg., 1987, 69, 59-60.

Revision Details

Revision AuthorDr S. Thomas
Revision No 1.3
Revision date1997/12/16

This datacard has been prepared from data provided by the manufacturer and/or from published literature.

All materials copyright © 1992-2007 by the Surgical Materials Testing Lab. unless otherwise stated.

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Last Modified: Thursday, 28-Mar-2002 10:23:05 GMT