Confused by the rules - keep DS home?

[GingerPCatt]

DH found out yesterday that someone he works with tested positive. DH had a meeting (about 30 min) with this person on Thursday and they were both masked. DH hasn't been contacted by test and trace, the person contacted him directly. DH can work from home so plans to self isolate just in case.
But I'm not sure if we should send DS to school or not tomorrow. As DH doesn't have any symptoms (so far - touch wood) he can't get a test. I don't want DS to miss school if he doesn't have to but I also don't want him to spread it either as some of his class mates have vulnerable family members.
What should we do? I can't find any official guidence on this situation.

Only your DH needs to self isolate.

As far as I know..... Your dh should self isolate if he was 2m or less from the other person. No one else in your house needs to unless your dh starts with symptoms.

Your DH is the primary contact, so your DS is secondary contact. DS doesn’t need to self isolate unless your DH develops symptoms.
Has the employer said anything to those in contact with the positive person?

Thanks for the replies.
DH was within 2 meters of the positive person for the duration of the meeting. His boss has sent an email around to the entire department and the other person in the meeting is self isolating as well.

@SocialBees

Only your DH needs to self isolate.

Technically not if masked.

Only your dh needs to isolate unless and until he himself shows symptoms.

It's only just been long enough since your dh was exposed for him to possibly start to have symptoms himself. Not quite long enough for you or your ds to be infectious, even if he's passed it to you already.