Sixteen-employe i-Point Technologies Ltd. of Washington will try to compete successfully with industry giants 3M Co. and Allied Corp. in offering an inexpensive monitor that can tell manufacturers, shippers, retailers and consumers the condition of perishable items ranging from pharmaceuticals to fresh seafood to milk to frozen pizza.

Officials of the local company believe the incidence of spoilage shows that its TTM, or time and temperature monitor, will have a ready market. Spoilage of between 15 and 20 percent of perishable products a year is not unusual, according to John W. Farquhar, vice president for scientific affairs at a Washington-based supermarket trade organization, the Food Marketing Institute.

Although i-Point expects to have its marketing force geared up early next year, a small number of customers have been using its TTM on a limited basis.

Golden Eye Seafoods of New Bedford, Mass., for example, has put TTMs on its shipping cartons for the past eight months and says that the TTMs have eliminated 90 percent of the company's spoilage problems. "No one in the perishables business can be without this," sales director Leon Sapuka said.

But the monitors could raise the question of who is to blame for spoilage, and some truckers reportedly have refused to carry goods that have monitors attached. "They can be perfectly reliable, but who wants to hear bad news?" asked a researcher at the American Frozen Food Institute.

The prototype i-Point TTMs are Band-Aid-size flexible plastic packets. An oval window on the right-hand side of the strip is surrounded by a rectangle divided into four segments, each with a different color.

The user learns the condition of the item to which the monitor is attached by comparing the color in the window with the colors in the rectangle. Green means the item is in excellent condition; yellow, good; yellow-red, uncertain; and red, overexposed to a combination of time and temperature.

The monitor contains one ampule of lipase, which is an enzyme, and one of lipid tricaproine, which is a substrate, or fatty substance. Pushing on the outside of the monitor breaks a membrane between the two ampules and starts a chemical reaction. The enzyme begins to break down the lipid to a fatty acid, causing a color change that is visible through the window.

The chemicals in a TTM are formulated differently according to what kind of item they will monitor, because pharmaceuticals and fresh fish, for example, react differently to time and temperature. Unit cost of the monitors will be between 3 and 50 cents, depending on the size of the order, which of 20 ready-mixed formulas the monitor contains, or whether it contains a custom-mixed formula. i-Point holds patents for the monitor in 28 countries.

Meanwhile, 3M Co. has just completed test-marketing its MonitorMark TTM, which contains a blotter of colored chemicals that gradually move down a wick in response to temperature changes. As in i-Point's TTM, the formulation differs according to the product being monitored. The unit cost ranges from 96 cents to $1.50. The MonitorMark has been available since last month, according to Dick Harris, 3M's market manager for food and drug packaging markets.

And Allied Corp. is testing chemicals sensitive to time and temperature that can be mixed with ink used for printing labels. Again, the formulation would differ for different products to be monitored, according to Abdul Razzaq, a senior development engineer. Allied representatives would not say when the ink additives would be available or what they would cost.

Washington businessman Silvester DeThomasis and D.C. attorney Arthur Gajarsa formed a group of investors and bought i-Point Inc. of Sweden in July 1981 from Kockums Shipyard of Malmo, Sweden, which had put it up for sale after being hit hard by the shipbuilding slump.