by the man accused of assaulting them -- is not toxic, an expert witness said yesterday.

"It is not a toxic substance,'' said Mr. Ralph Helmrich, a chemical engineer and owner of Washington Laboratories, who developed the ingredients and produced the Chemical Shield spray.

"It does not come under the toxicity guidelines of the US Consumer Product Safety guidelines.'' David Anthony Brangman, 31, has pleaded not guilty to assaulting P.c. James Walters and P.c. James Outerbridge with intent to do them bodily harm on Ord Road on June 11, 1992.

He has further denied importing and possessing the canister of Chemical Shield, designed for the discharge of a noxious liquid and a prohibited weapon under the Firearms Act.

He has also denied charges of offensive behaviour and violently resisting arrest.

Mr. Helmrich yesterday gave evidence on the effects of the spray containing CS gas, used as an anti-riot agent. He said the chemical was non-toxic and caused no permanent harm to human beings.

Pain, irritation, tightness in the chest and tears -- the temporary effects of the spray -- wear off after about 15 minutes, he said, adding that the effects of the chemical were uncomfortable but not disabling.

The jury, which will be asked to reach a verdict next week, will have to rule on whether the canister of Chemical Shield used by Brangman contained a noxious liquid.

Brangman, represented by lawyer Mr. Michael Scott, claims he acted in self-defence when he sprayed the two Police officers in their faces, leaving them choking and crying.

Prior to the incident, Brangman said he was harassed constantly by the Police.

Weekly visits by Police officers investigating complaints that he pedalled drugs and laundered drugs money from his Middle Road candy store drove him to complain to the Police Commissioner.

In his testimony this week, Brangman claimed P.c. Walters and P.c.

Outerbridge held and beat him with a stick. When asked in a Police statement the day of the incident if he had been beaten by the officers, he answered he had not.

P.c. Walters and P.c. Outerbridge said they acted according to Police procedure when they attempted to arrest Brangman for offensive behaviour early on June 11.

They said they approached Brangman who was using a pubic telephone outside Lines Grocery on Ord Road for a routine warrant check.

As they waited for the results, Brangman became verbally abusive, hurling racial insults at the officers.

When they attempted to arrest him, Brangman sprayed P.c. Walters and then P.c.

Outerbridge in the face. He then ran off laughing.

Yesterday, Mr. Scott summed up his case for the defence.

He said the chemical elements in the spray were not harmful and Brangman had acted in self-defence.

"My submission is that David Brangman was doing nothing wrong -- merely using the telephone.'' But Crown Counsel Mr. Khamisi Tokumbo for the Crown argued that the spray was designed to disable the officers temporarily and that they had behaved correctly.

"Did they approach Mr. Brangman in the wrong way or were they just doing their duty? It does not mean they were wrong for just stopping and making inquiries,'' Mr. Tokumbo said.

He also pointed out inconsistencies in Brangman's evidence and that of other defence witnesses.